Bump to version v8.0.0

* Removed some entries that were fixes for the nigthly versions, not
stable versions.
* Reference the actual issue number(not the PR number) on some entries
* Remove duplicate entries
* Clarify some entries
* Grouped CLI entries

.circleci/config.yml

@@ -1,59 +1,39 @@
 version: 2
 
-build-distro-bin: &build-distro-bin
-  machine: true
-  steps:
-    - checkout
-    # cannot interpolate env var and use as a cache key so just copy the Dockerfile to another filename
-    - run: cp docker/distro_release/Dockerfile.$CIRCLE_JOB docker/distro_release/Dockerfile
-    - restore_cache:
-        keys:
-        - v1-{{ .Environment.CIRCLE_JOB }}-image-{{ checksum "docker/distro_release/Dockerfile" }}
-    - restore_cache:
-        keys:
-        - v1-{{ .Environment.CIRCLE_JOB }}-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
-    - run:
-        name: load or build docker image
-        command: |
-          if [[ -e ~/image.tar ]]; then
-            docker load -i ~/image.tar
-          else
-            docker build --rm=false -t $CIRCLE_JOB -f docker/distro_release/Dockerfile.$CIRCLE_JOB docker/distro_release/
-            docker save $CIRCLE_JOB > ~/image.tar
-          fi
-    - run:
-        name: build binary
-        command: |
-          docker run -it \
-            -v $HOME/.stack:/root/.stack \
-            -v $(pwd):/source \
-            -v $HOME/bin/:/root/.local/bin/ \
-            $CIRCLE_JOB build --allow-different-user --install-ghc --copy-bins
-          # volumes owned by root if chown is not done the save_cache step fails silently
-          sudo chown -R circleci:circleci ~/.stack .stack-work
-    - run:
-        name: compress binary
-        command: |
-          mkdir -p /tmp/workspace/bin
-          cd /tmp/workspace/bin
-          tar cvJf postgrest-$CIRCLE_TAG-$CIRCLE_JOB.tar.xz -C ~/bin postgrest
-    - persist_to_workspace:
-        root: /tmp/workspace
-        paths:
-          - bin/*
-    - save_cache:
-        paths:
-          - ~/image.tar
-        key: v1-{{ .Environment.CIRCLE_JOB }}-image-{{ checksum "docker/distro_release/Dockerfile" }}
-    - save_cache:
-        paths:
-          - "~/.stack"
-          - ".stack-work"
-        key: v1-{{ .Environment.CIRCLE_JOB }}-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
-
 jobs:
-  build-test:
-    machine: true
+  # Make sure that there are no outstanding linting hints and that
+  # auto-formatting does not result in any changes.
+  style-check:
+    docker:
+      - image: nixos/nix:2.3
+    steps:
+      - checkout
+      - run:
+          name: Install linting and styling scripts
+          command: nix-env -f default.nix -iA style
+      - run:
+          name: Run linter
+          command: |
+            # Note: For checking this locally, use `nix-shell --run postgrest-lint`
+            postgrest-lint
+      - run:
+          name: Run style check
+          command: |
+            # 'Note: For checking this locally, use `nix-shell --run postgrest-style`
+            postgrest-style-check
+
+  # Run tests based on stack and docker against the oldest PostgreSQL version
+  # that we support.
+  stack-test:
+    docker:
+      - image: cimg/base:2021.03
+        environment:
+          - PGHOST=localhost
+      - image: circleci/postgres:9.5
+        environment:
+          - POSTGRES_USER=circleci
+          - POSTGRES_DB=circleci
+          - POSTGRES_HOST_AUTH_METHOD=trust
     steps:
       - checkout
       - restore_cache:
@@ -62,127 +42,235 @@ jobs:
       - run:
           name: install stack & dependencies
           command: |
-            curl -L https://github.com/commercialhaskell/stack/releases/download/v1.1.2/stack-1.1.2-linux-x86_64.tar.gz | tar zx -C /tmp
-            sudo mv /tmp/stack-1.1.2-linux-x86_64/stack /usr/bin
+            curl -L https://github.com/commercialhaskell/stack/releases/download/v2.3.1/stack-2.3.1-linux-x86_64.tar.gz | tar zx -C /tmp
+            sudo mv /tmp/stack-2.3.1-linux-x86_64/stack /usr/bin
             sudo apt-get update
-            sudo apt-get install libgmp-dev
-            sudo apt-get install --only-upgrade binutils
+            sudo apt-get install -y libgmp-dev postgresql-client
+            sudo apt-get install -y --only-upgrade binutils
             stack setup
-            rm -rf $(stack path --dist-dir) $(stack path --local-install-root)
-            stack install hlint packdeps cabal-install
+      - run:
+          name: build src and tests dependencies
+          command: |
+            stack build --fast -j1 --only-dependencies
+            stack build --fast --test --no-run-tests --only-dependencies
+      - save_cache:
+          paths:
+            - "~/.stack"
+            - ".stack-work"
+          key: v1-stack-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
       - run:
           name: build src and tests
           command: |
             stack build --fast -j1
             stack build --fast --test --no-run-tests
       - run:
-          name: run tests
+          name: run spec tests
           command: |
-            sudo service postgresql start
-            POSTGREST_TEST_CONNECTION=$(test/create_test_db "postgres://circleci@localhost" postgrest_test) stack test
-            test/io-tests.sh
-      - run:
-          name: run linter
-          command: git ls-files | grep '\.l\?hs$' | xargs stack exec -- hlint -X QuasiQuotes -X NoPatternSynonyms "$@"
-      - run:
-          name: extra checks
-          command: |
-            stack exec -- cabal update
-            stack exec --no-ghc-package-path -- cabal install --only-d --dry-run
-            stack exec -- packdeps *.cabal || true
-            stack exec -- cabal check
-            stack haddock --no-haddock-deps
-            stack sdist
-      - save_cache:
-          paths:
-            - "~/.stack"
-            - ".stack-work"
-          key: v1-stack-dependencies-{{ checksum "postgrest.cabal" }}-{{ checksum "stack.yaml" }}
-
-  centos6:
-    <<: *build-distro-bin
-
-  centos7:
-    <<: *build-distro-bin
-
-  ubuntu:
-    <<: *build-distro-bin
-
-  ubuntui386:
-    <<: *build-distro-bin
+            test/create_test_db "postgres://circleci@localhost" postgrest_test stack test
+      - store_artifacts:
+          path: /tmp/postgrest
 
+  # Publish a new release. This only runs when a release is tagged (see
+  # workflow below).
   release:
-    docker:
-      - image: circleci/golang:1.8
+    machine: true
     steps:
-      - attach_workspace:
-          at: /tmp/workspace
       - checkout
       - run:
-          name: add body and tars to github release
+          name: Install Nix
           command: |
-            go get -u github.com/tcnksm/ghr
-            START=$(echo $CIRCLE_TAG | cut -c2-)
-            END='## \['
-            BODY=$(sed -n "1,/$START/d;/$END/q;p" CHANGELOG.md)
-            ghr -t $GITHUB_TOKEN -u $CIRCLE_PROJECT_USERNAME -r $CIRCLE_PROJECT_REPONAME -b "$BODY" --replace $CIRCLE_TAG /tmp/workspace/bin
-      - setup_remote_docker
+            curl -L https://nixos.org/nix/install | sh
+            echo "source $HOME/.nix-profile/etc/profile.d/nix.sh" >> $BASH_ENV
       - run:
-          name: publish docker image
+          name: Change postgrest.cabal if nightly
           command: |
-            docker build --build-arg POSTGREST_VERSION=$CIRCLE_TAG -t postgrest ./docker/
-            docker login -u $DOCKER_USER -p $DOCKER_PASS
-            docker tag postgrest postgrest/postgrest:$CIRCLE_TAG
-            docker push postgrest/postgrest:$CIRCLE_TAG
-            docker tag postgrest postgrest/postgrest:latest
-            docker push postgrest/postgrest:latest
+            if test "$CIRCLE_TAG" = "nightly"
+            then
+              cabal_nightly_version=$(git show -s --format='%cd' --date='format:%Y%m%d')
+              sed -i "s/^version:.*/version:$cabal_nightly_version/" postgrest.cabal
+            fi
+      - run:
+          name: Install and use the Cachix binary cache
+          command: |
+            nix-env -iA cachix -f https://cachix.org/api/v1/install
+            cachix use postgrest
+      - run:
+          name: Install release scripts
+          command: nix-env -f default.nix -iA release
+      - run:
+          name: Publish GitHub release
+          command: |
+            export GITHUB_USERNAME="$CIRCLE_PROJECT_USERNAME"
+            export GITHUB_REPONAME="$CIRCLE_PROJECT_REPONAME"
+            postgrest-release-github $CIRCLE_TAG
+      - run:
+          name: Publish Docker images
+          command: |
+            export DOCKER_REPO=postgrest
+            postgrest-release-docker-login
+            postgrest-release-dockerhub $CIRCLE_TAG
+            if test "$CIRCLE_TAG" != "nightly"
+            then
+              postgrest-release-dockerhub-description
+            fi
+      - store_artifacts:
+          path: /tmp/postgrest
+
+  # Build everything in default.nix and push to the Cachix binary cache if running on main
+  nix-build:
+    machine: true
+    steps:
+      - checkout
+      - run:
+          name: Install Nix
+          command: |
+            curl -L https://nixos.org/nix/install | sh
+            echo "source $HOME/.nix-profile/etc/profile.d/nix.sh" >> $BASH_ENV
+      - run:
+          name: Install and use the Cachix binary cache
+          command: |
+            nix-env -iA cachix -f https://cachix.org/api/v1/install
+            cachix use postgrest
+      - run:
+          name: Change postgrest.cabal if nightly
+          command: |
+            if test "$CIRCLE_TAG" = "nightly"
+            then
+              cabal_nightly_version=$(git show -s --format='%cd' --date='format:%Y%m%d')
+              sed -i "s/^version:.*/version:$cabal_nightly_version/" postgrest.cabal
+            fi
+      - run:
+          name: Build all derivations from default.nix and push results to Cachix
+          command: |
+            # Only push to the cache when CircleCI makes the CACHIX_SIGNING_KEY
+            # available (e.g. not for pull requests).
+            if [ -n "${CACHIX_AUTH_TOKEN:-""}" ]; then
+              echo "Building and caching all derivations..."
+              cachix authtoken "$CACHIX_AUTH_TOKEN"
+
+              # Push new builds as we go
+              nix-build | cachix push postgrest
+
+              # Make sure that everything, including .drv files, is pushed
+              nix-env -f default.nix -iA devTools
+              postgrest-push-cachix
+            else
+              echo "Building all derivations (caching skipped for outside pull requests)..."
+              nix-build
+            fi
+      - store_artifacts:
+          path: /tmp/postgrest
+
+  # Run tests
+  nix-test:
+    machine: true
+    steps:
+      - checkout
+      - run:
+          name: Install Nix
+          command: |
+            curl -L https://nixos.org/nix/install | sh
+            echo "source $HOME/.nix-profile/etc/profile.d/nix.sh" >> $BASH_ENV
+      - run:
+          name: Install and use the Cachix binary cache
+          command: |
+            nix-env -iA cachix -f https://cachix.org/api/v1/install
+            cachix use postgrest
+      - run:
+          name: Install testing scripts
+          command: nix-env -f default.nix -iA tests memory withTools
+      - run:
+          name: Run coverage (io tests and spec tests against PostgreSQL 13)
+          command: postgrest-coverage
+          when: always
+      - run:
+          name: Skip tests on build or primary test failure
+          command: circleci-agent step halt
+          when: on_fail
+      - run:
+          name: Upload coverage to codecov
+          command: |
+            # Modified from:
+            # https://docs.codecov.io/docs/about-the-codecov-bash-uploader#validating-the-bash-script
+            curl -s https://codecov.io/bash > codecov;
+            VERSION=$(grep 'VERSION=\".*\"' codecov | cut -d'"' -f2);
+            shasum -a 512 -c <(curl -s https://raw.githubusercontent.com/codecov/codecov-bash/${VERSION}/SHA512SUM | grep codecov)
+            bash codecov -f coverage/codecov.json
+      - run:
+          name: Run the spec tests against PostgreSQL 12
+          command: postgrest-with-postgresql-12 postgrest-test-spec
+          when: always
+      - run:
+          name: Run the spec tests against PostgreSQL 11
+          command: postgrest-with-postgresql-11 postgrest-test-spec
+          when: always
+      - run:
+          name: Run the spec tests against PostgreSQL 10
+          command: postgrest-with-postgresql-10 postgrest-test-spec
+          when: always
+      - run:
+          name: Run the spec tests against PostgreSQL 9.6
+          command: postgrest-with-postgresql-9.6 postgrest-test-spec
+          when: always
+      - run:
+          name: Run the spec tests against PostgreSQL 9.5
+          command: postgrest-with-postgresql-9.5 postgrest-test-spec
+          when: always
+      - run:
+          name: Check the spec tests for idempotence
+          command: postgrest-test-spec-idempotence
+          when: always
+      - run:
+          name: Run memory tests
+          command: postgrest-test-memory
+          when: always
+      - store_artifacts:
+          path: /tmp/postgrest
 
 workflows:
   version: 2
   build-test-release:
     jobs:
-      - build-test:
+      - style-check:
+          # Make sure that this job also runs when releases are tagged.
           filters:
             tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-      - centos6:
-          requires:
-            - build-test
+              only:
+                - /v[0-9]+(\.[0-9]+)*/
+                - nightly
+      - stack-test:
           filters:
             tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-            branches:
-              ignore: /.*/
-      - centos7:
-          requires:
-            - build-test
+              only:
+                - /v[0-9]+(\.[0-9]+)*/
+                - nightly
+      - nix-build:
           filters:
             tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-            branches:
-              ignore: /.*/
-      - ubuntu:
-          requires:
-            - build-test
+              only:
+                - /v[0-9]+(\.[0-9]+)*/
+                - nightly
+          context:
+            - cachix
+      - nix-test:
           filters:
             tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-            branches:
-              ignore: /.*/
-      - ubuntui386:
-          requires:
-            - build-test
-          filters:
-            tags:
-              only: /v[0-9]+(\.[0-9]+)*/
-            branches:
-              ignore: /.*/
+              only:
+                - /v[0-9]+(\.[0-9]+)*/
+                - nightly
       - release:
           requires:
-            - centos6
-            - centos7
-            - ubuntu
-            - ubuntui386
+            - style-check
+            - stack-test
+            - nix-build
+            - nix-test
           filters:
             tags:
-              only: /v[0-9]+(\.[0-9]+)*/
+              only:
+                - /v[0-9]+(\.[0-9]+)*/
+                - nightly
+            branches:
+              ignore: /.*/
+          context:
+            - docker
+            - github

.cirrus.yml

@@ -0,0 +1,71 @@
+freebsd_instance:
+  image: freebsd-12-2-release-amd64
+
+build_task:
+  env:
+    GITHUB_TOKEN: ENCRYPTED[!1ecc3020fe8c6463c06ebc22153533239e132ee56e4faad95ce336bd2ee2bde6aa89c0352e89faaa2c10f4a5bac9b7fc!]
+  # caches the freebsd package downloads
+  # saves probably just a couple of seconds, but hey...
+  pkg_cache:
+    folder: /var/cache/pkg
+
+  install_script:
+  #  - pkg update
+    - pkg install -y postgresql12-client ghc hs-cabal-install jq git
+
+  # cache the hackage index file and downloads which are
+  # cabal v2-update downloads an incremental update, so we don't need to keep this up2date
+  packages_cache:
+    # warning: don't use ~/.cabal here, this will break the cache
+    folder: /.cabal/packages
+    reupload_on_changes: false
+
+  # cache the dependencies built by cabal
+  # they have to be uploaded on every change to make the next build fast
+  store_cache:
+    # warning: don't use ~/.cabal here, this will break the cache
+    folder: /.cabal/store
+    fingerprint_script: cat postgrest.cabal
+    reupload_on_changes: true
+
+  build_script:
+    - cabal v2-update
+    - |
+      if test "$CIRRUS_TAG" = "nightly"
+      then
+        cabal_nightly_version=$(git show -s --format='%cd' --date='format:%Y%m%d')
+        sed -i '' "s/^version:.*/version:$cabal_nightly_version/" postgrest.cabal
+      fi
+      ## compile for 30 minutes tops
+    - timeout 1800 cabal v2-build -j1 || test "$?" = "124"
+
+  publish_script:
+    - |
+      if test ! "$CIRRUS_TAG"
+      then
+        echo 'No tag pushed. Skip release.'
+      else
+        cabal v2-install
+
+        bin_name=""
+
+        if test $CIRRUS_TAG = "nightly"
+        then
+          suffix=$(git show -s --format="%cd-%h" --date="format:%Y-%m-%d-%H-%M")
+          bin_name=postgrest-nightly-$suffix-freebsd.tar.xz
+        else
+          bin_name=postgrest-$CIRRUS_TAG-freebsd.tar.xz
+        fi
+
+        release_id=$(curl -s https://api.github.com/repos/$CIRRUS_REPO_FULL_NAME/releases/tags/$CIRRUS_TAG | jq .id)
+
+        echo "Uploading $bin_name to gh release: $release_id"
+
+        tar cvJf $bin_name --dereference -C /.cabal/bin postgrest
+
+        ## We don't use ghr here because it doesn't provide freebsd binaries: https://github.com/tcnksm/ghr/issues/127
+        curl -X POST --data-binary @$bin_name \
+          -H "Authorization:token $GITHUB_TOKEN" \
+          -H "Content-Type:application/octet-stream" \
+          "https://uploads.github.com/repos/$CIRRUS_REPO_FULL_NAME/releases/$release_id/assets?name=$bin_name"
+      fi

.codecov.yml

@@ -0,0 +1,18 @@
+codecov:
+  branch: main
+  require_ci_to_pass: false
+
+comment: false
+
+coverage:
+  status:
+    project:
+      default:
+        target: auto
+        threshold: 0%
+        only_pulls: false
+    patch:
+      default:
+        target: auto
+        threshold: 0%
+        only_pulls: true

.github/CONTRIBUTING.md

@@ -15,14 +15,14 @@ your contributions.
 
 ## Issues
 
+For questions on how to use PostgREST, please use
+[GitHub discussions](https://github.com/PostgREST/postgrest/discussions).
+
 ### Reporting an Issue
 
-* Make sure you test against the latest released version. It is possible
-  we already fixed the bug you're experiencing.
-
-* Also check the `CHANGELOG.md` to see if any unreleased changes affect
-  the issue. The very newest changes can take a little while to be released
-  as a new official version.
+* Make sure you test against the latest [stable release](https://github.com/PostgREST/postgrest/releases/latest)
+  and also against the latest [nightly release](https://github.com/PostgREST/postgrest/releases/tag/nightly).
+  It is possible we already fixed the bug you're experiencing.
 
 * Provide steps to reproduce the issue, including your OS version and
   the specific database schema that you are using.
@@ -32,38 +32,24 @@ your contributions.
   then [find your logs](http://blog.endpoint.com/2014/11/dear-postgresql-where-are-my-logs.html).
 
 * If your database schema has changed while the PostgREST server is running,
-  send the server a `SIGHUP` signal or restart it to ensure the schema cache
+  [send the server a `SIGUSR1` signal](http://postgrest.org/en/latest/admin.html#schema-reloading) or restart it to ensure the schema cache
   is not stale. This sometimes fixes apparent bugs.
 
 ## Code
 
+We have a fully nix-based development environment with many tools for a smooth development workflow available.
+Check the [development docs](https://github.com/PostgREST/postgrest/blob/main/nix/README.md) on how to set it up and use it.
+
 ### Haskell Conventions
 
 * All contributions must pass the tests before being merged. When
   you create a pull request your code will automatically be tested.
 
-* All code must also pass [hlint](http://community.haskell.org/~ndm/hlint/)
-  with no warnings. This helps enforce a uniform style for all
-  committers. Continuous integration will check this as well on every
-  pull request.
+* All code must also pass [hlint](http://community.haskell.org/~ndm/hlint/) and [stylish-haskell](https://github.com/jaspervdj/stylish-haskell)
+  with no warnings. This helps enforce a uniform style for all committers. Continuous integration will check this as well on every
+  pull request. There are useful tools in the nix-shell that help with checking this locally. You can run `postgrest-check` to do this manually but
+  we recommend adding it to `.git/hooks/pre-commit` as `nix-shell --run postgrest-check` to automatically check this before doing a commit.
 
-* For help building the Haskell code on your computer check out the [building from
-source](https://postgrest.com/en/stable/install.html#build-from-source)
-wiki page.
+### Running Tests
 
-## Maintenance
-
-### Schedule
-
-Currently I (@begriffs) am the sole maintainer, and while I am
-overjoyed to help resolve issues I also have to balance this with
-my other obligations.  If you don't get a response right away
-don't worry, I will definitely get to it. Also you can join the
-Gitter [chat room](https://gitter.im/begriffs/postgrest) to
-discuss issues you are having.
-
-## Running Tests
-
-For instructions on running tests, see the official docs hosted here:
-
-https://postgrest.com/en/stable/install.html#postgrest-test-suite
+For instructions on running tests, see the [development docs](https://github.com/PostgREST/postgrest/blob/main/nix/README.md#testing).

.github/FUNDING.yml

@@ -0,0 +1,3 @@
+# These are supported funding model platforms
+
+patreon: postgrest

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,17 @@
+<!--
+Before reporting a bug:
+If your database schema has changed while the PostgREST server is running,
+send the server a SIGUSR1 signal or restart it(http://postgrest.org/en/stable/admin.html#schema-reloading)
+to ensure the schema cache is not stale. This sometimes fixes apparent bugs.
+-->
+### Environment
+
+* PostgreSQL version: (if using docker, specify the image)
+* PostgREST version: (if using docker, specify the image)
+* Operating system:
+
+### Description of issue
+
+(Expected behavior vs actual behavior)
+
+(Steps to reproduce: Include a minimal SQL definition plus how you make the request to PostgREST and the response body)

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,6 @@
+<!--
+When submitting a new feature or fix:
+
+- Add a new entry to the CHANGELOG - https://github.com/PostgREST/postgrest/blob/main/CHANGELOG.md#unreleased
+- If relevant, update the docs     - https://github.com/PostgREST/postgrest-docs
+-->

.gitignore

@@ -12,3 +12,12 @@ site
 *~
 *#*
 .#*
+*.swp
+result*
+dist-newstyle
+postgrest.hp
+postgrest.prof
+__pycache__
+*.tix
+coverage
+.hpc

.stylish-haskell.yaml

@@ -39,9 +39,9 @@ steps:
       # - none: Do not perform any alignment.
       #
       # Default: global.
-      align: global
+      align: group
 
-      # Folowing options affect only import list alignment.
+      # The following options affect only import list alignment.
       #
       # List align has following options:
       #
@@ -64,6 +64,25 @@ steps:
       # Default: after_alias
       list_align: after_alias
 
+      # Right-pad the module names to align imports in a group:
+      #
+      # - true: a little more readable
+      #
+      #   > import qualified Data.List       as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #   > import qualified Data.List.Extra as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #
+      # - false: diff-safe
+      #
+      #   > import qualified Data.List as List (concat, foldl, foldr, init,
+      #   >                                     last, length)
+      #   > import qualified Data.List.Extra as List (concat, foldl, foldr,
+      #   >                                           init, last, length)
+      #
+      # Default: true
+      pad_module_names: true
+
       # Long list align style takes effect when import is too long. This is
       # determined by 'columns' setting.
       #
@@ -75,7 +94,7 @@ steps:
       #   short enough to fit to single line. Otherwise it'll be multiline.
       #
       # - multiline: One line per import list entry.
-      #   Type with contructor list acts like single import.
+      #   Type with constructor list acts like single import.
       #
       #   > import qualified Data.Map as M
       #   >     ( empty
@@ -109,7 +128,7 @@ steps:
       #   Useful for 'file' and 'group' align settings.
       list_padding: 4
 
-      # Separate lists option affects formating of import list for type
+      # Separate lists option affects formatting of import list for type
       # or class. The only difference is single space between type and list
       # of constructors, selectors and class functions.
       #
@@ -126,6 +145,22 @@ steps:
       # Default: true
       separate_lists: true
 
+      # Space surround option affects formatting of import lists on a single
+      # line. The only difference is single space after the initial
+      # parenthesis and a single space before the terminal parenthesis.
+      #
+      # - true: There is single space associated with the enclosing
+      #   parenthesis.
+      #
+      #   > import Data.Foo ( foo )
+      #
+      # - false: There is no space associated with the enclosing parenthesis
+      #
+      #   > import Data.Foo (foo)
+      #
+      # Default: false
+      space_surround: false
+
   # Language pragmas
   - language_pragmas:
       # We can generate different styles of language pragma lists.
@@ -142,7 +177,7 @@ steps:
 
       # Align affects alignment of closing pragma brackets.
       #
-      # - true: Brackets are aligned in same collumn.
+      # - true: Brackets are aligned in same column.
       #
       # - false: Brackets are not aligned together. There is only one space
       #   between actual import and closing bracket.

.travis.yml

@@ -2,63 +2,79 @@ language: generic
 
 sudo: false
 
-os:
-- osx
-
-cache:
-  timeout: 1000
-  directories:
-    - $HOME/.stack
-    - $HOME/.local/bin
-
-before_install:
-- mkdir -p "$HOME/.local/bin"
-- export PATH="$PATH:$HOME/.local/bin"
-
-install:
-- |
-  if test -f "$HOME/.local/bin/stack"
-    then
-      echo 'Stack is already installed.'
-    else
-      echo "Installing Stack..."
-      travis_retry curl -L https://www.stackage.org/stack/osx-x86_64 > stack.tar.gz
-      gunzip stack.tar.gz
-      tar -x -f stack.tar --strip-components 1
-      mv stack "$HOME/.local/bin/"
-      rm stack.tar
-  fi
-- |
-  if test -f "$HOME/.local/bin/ghr"
-  then
-    echo 'ghr is already installed.'
-  else
-    echo "Installing ghr..."
-    travis_retry curl -L https://github.com/tcnksm/ghr/releases/download/v0.5.4/ghr_v0.5.4_darwin_386.zip > ghr.zip
-    unzip ghr.zip -d "$HOME/.local/bin"
-    rm ghr.zip
-  fi
-
-script:
-- gtimeout 1800 stack build --no-terminal --only-snapshot --install-ghc || true
-- |
-  if test ! "$TRAVIS_TAG"
-  then
-    echo 'No tag pushed. Skipping build.'
-  else
-    stack build --no-terminal --copy-bins --local-bin-path .
-  fi
-- |
-  if test ! "$TRAVIS_TAG"
-  then
-    echo 'No tag pushed. Skipping release.'
-  else
-    OWNER="$(echo "$TRAVIS_REPO_SLUG" | cut -f1 -d/)"
-    REPO="$(echo "$TRAVIS_REPO_SLUG" | cut -f2 -d/)"
-    START=$(echo $TRAVIS_TAG | cut -c2-)
-    END='## \['
-    BODY=$(sed -n "1,/$START/d;/$END/q;p" CHANGELOG.md)
-    strip postgrest
-    tar cjf postgrest-$TRAVIS_TAG-osx.tar.xz postgrest
-    ghr -t $GITHUB_TOKEN -u $OWNER -r $REPO -b "$BODY"--replace $TRAVIS_TAG postgrest-$TRAVIS_TAG-osx.tar.xz
-  fi
+jobs:
+  include:
+    - name: Build OSX Binary
+      os: osx
+      cache:
+        timeout: 1000
+        directories:
+          - $HOME/.stack
+          - $HOME/.local/bin
+      before_install:
+        - mkdir -p "$HOME/.local/bin"
+        - export PATH="$PATH:$HOME/.local/bin"
+      install:
+        - |
+          if test -f "$HOME/.local/bin/stack"
+            then
+              echo 'Stack is already installed.'
+            else
+              echo "Installing Stack..."
+              travis_retry curl -L https://www.stackage.org/stack/osx-x86_64 > stack.tar.gz
+              gunzip stack.tar.gz
+              tar -x -f stack.tar --strip-components 1
+              mv stack "$HOME/.local/bin/"
+              rm stack.tar
+          fi
+        - |
+          if test -f "$HOME/.local/bin/ghr"
+          then
+            echo 'ghr is already installed.'
+          else
+            echo "Installing ghr..."
+            travis_retry curl -L https://github.com/tcnksm/ghr/releases/download/v0.5.4/ghr_v0.5.4_darwin_386.zip > ghr.zip
+            unzip ghr.zip -d "$HOME/.local/bin"
+            rm ghr.zip
+          fi
+      script:
+        - |
+          if test "$TRAVIS_TAG" = "nightly"
+          then
+            cabal_nightly_version=$(git show -s --format='%cd' --date='format:%Y%m%d')
+            sed -i '' "s/^version:.*/version:$cabal_nightly_version/" postgrest.cabal
+          fi
+        ## Building the whole project can take longer than 50 minutes. Since Travis has a global timeout of 50 minutes
+        ## we compile for 30 minutes tops(`gtimeout 1800`) and quit compiling with no error.
+        ## Since we CACHE the compile results we can continue compiling from where we left off
+        ## on the next commit.
+        - gtimeout 1800 stack build --no-terminal --only-snapshot --install-ghc || (($?==124))
+        - |
+          if test ! "$TRAVIS_TAG"
+          then
+            echo 'No tag pushed. Skip building binary.'
+          else
+            stack build --no-terminal --copy-bins --local-bin-path .
+          fi
+        - |
+          if test ! "$TRAVIS_TAG"
+          then
+            echo 'No tag pushed. Skipping release.'
+          else
+            owner="$(echo "$TRAVIS_REPO_SLUG" | cut -f1 -d/)"
+            repo="$(echo "$TRAVIS_REPO_SLUG" | cut -f2 -d/)"
+            if test $TRAVIS_TAG = "nightly"
+            then
+              suffix=$(git show -s --format="%cd-%h" --date="format:%Y-%m-%d-%H-%M")
+              strip postgrest
+              tar cJf postgrest-nightly-$suffix-osx.tar.xz postgrest
+              ghr -t $GITHUB_TOKEN -u $owner -r $repo --replace nightly postgrest-nightly-$suffix-osx.tar.xz
+            else
+              start=$TRAVIS_TAG
+              end='## \['
+              body=$(sed -n "1,/$start/d;/$end/q;p" CHANGELOG.md)
+              strip postgrest
+              tar cJf postgrest-$TRAVIS_TAG-osx.tar.xz postgrest
+              ghr -t $GITHUB_TOKEN -u $owner -r $repo -b "$body"--replace $TRAVIS_TAG postgrest-$TRAVIS_TAG-osx.tar.xz
+            fi
+          fi

BACKERS.md

@@ -0,0 +1,85 @@
+# Sponsors & Backers
+
+PostgREST ongoing development is only possible thanks to our Sponsors and Backers, listed below. If you'd like to join them, you can do so by supporting the PostgREST organization on [Patreon](https://www.patreon.com/postgrest).
+
+## Sponsors
+
+<table>
+  <tbody>
+    <tr>
+      <td align="center" valign="middle">
+        <a href="https://www.cybertec-postgresql.com/en/?utm_source=postgrest.org&utm_medium=referral&utm_campaign=postgrest" target="_blank">
+          <img width="222px" src="static/cybertec-new.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://www.2ndquadrant.com/en/?utm_campaign=External%20Websites&utm_source=PostgREST&utm_medium=Logo" target="_blank">
+          <img width="296px" src="static/2ndquadrant.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://tryretool.com/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="static/retool.png">
+        </a>
+      </td>
+    </tr>
+    <tr></tr>
+    <tr>
+      <td align="center" valign="middle">
+        <a href="https://gnuhost.eu/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="static/gnuhost.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://supabase.io?utm_source=postgrest%20backers&utm_medium=open%20source%20partner&utm_campaign=postgrest%20backers%20github&utm_term=homepage" target="_blank">
+          <img width="296px" src="static/supabase.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://oblivious.ai/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="static/oblivious.jpg">
+        </a>
+      </td>
+    </tr>
+  </tbody>
+</table>
+
+## Lead Backers
+
+- Evans Fernandes
+- [Jan Sommer](https://github.com/nerfpops)
+- [Franz Gusenbauer](https://www.igutech.at/)
+
+## Backers
+
+- Tsingson Qin
+- Michel Pelletier
+- Jay Hannah
+- Robert Stolarz
+- Nicholas DiBiase
+- Christopher Reid
+- Nathan Bouscal
+- Daniel Rafaj
+- David Fenko
+- Remo Rechkemmer
+- Severin Ibarluzea
+- Tom Saleeba
+- Pawel Tyll
+
+## Former Backers
+
+<table>
+  <tbody>
+    <tr>
+      <td align="center" valign="middle">
+        <a href="https://www.timescale.com?utm_campaign=postgrest&utm_source=sponsor&utm_medium=referral&utm_content=github" target="_blank">
+          <img width="222px" src="static/timescaledb.png">
+        </a>
+      </td>
+    </tr>
+  </tbody>
+</table>
+
+- [Christiaan Westerbeek](https://devotis.nl)
+- [Daniel Babiak](https://github.com/dbabiak)
+- Kofi Gumbs

CHANGELOG.md

@@ -9,6 +9,276 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+## [8.0.0] - 2021-07-25
+
+### Added
+
+ - #1525, Allow http status override through response.status guc - @steve-chavez
+ - #1512, Allow schema cache reloading with NOTIFY - @steve-chavez
+ - #1119, Allow config file reloading with SIGUSR2 - @steve-chavez
+ - #1558, Allow 'Bearer' with and without capitalization as authentication schema - @wolfgangwalther
+ - #1470, Allow calling RPC with variadic argument by passing repeated params - @wolfgangwalther
+ - #1559, No downtime when reloading the schema cache with SIGUSR1 - @steve-chavez
+ - #504, Add `log-level` config option. The admitted levels are: crit, error, warn and info - @steve-chavez
+ - #1607, Enable embedding through multiple views recursively - @wolfgangwalther
+ - #1598, Allow rollback of the transaction with Prefer tx=rollback - @wolfgangwalther
+ - #1633, Enable prepared statements for GET filters. When behind a connection pooler, you can disable preparing with `db-prepared-statements=false`
+   + This increases throughput by around 30% for simple GET queries(no embedding, with filters applied).
+ - #1729, #1760, Get configuration parameters from the db and allow reloading config with NOTIFY  - @steve-chavez
+ - #1824, Allow OPTIONS to generate certain HTTP methods for a DB view - @laurenceisla
+ - #1872, Show timestamps in startup/worker logs - @steve-chavez
+ - #1881, Add `openapi-mode` config option that allows ignoring roles privileges when showing the OpenAPI output - @steve-chavez
+ - CLI options(for debugging):
+   + #1678, Add --dump-config CLI option that prints loaded config and exits - @wolfgangwalther
+   + #1691, Add --example CLI option to show example config file - @wolfgangwalther
+   + #1697, #1723, Add --dump-schema CLI option for debugging purposes - @monacoremo, @wolfgangwalther
+ - #1794, (Experimental) Add `request.spec` GUC for db-root-spec - @steve-chavez
+
+### Fixed
+
+ - #1592, Removed single column restriction to allow composite foreign keys in join tables - @goteguru
+ - #1530, Fix how the PostgREST version is shown in the help text when the `.git` directory is not available - @monacoremo
+ - #1094, Fix expired JWTs starting an empty transaction on the db - @steve-chavez
+ - #1162, Fix location header for POST request with select= without PK - @wolfgangwalther
+ - #1585, Fix error messages on connection failure for localized postgres on Windows - @wolfgangwalther
+ - #1636, Fix `application/octet-stream` appending `charset=utf-8` - @steve-chavez
+ - #1469, #1638 Fix overloading of functions with unnamed arguments - @wolfgangwalther
+ - #1560, Return 405 Method not Allowed for GET of volatile RPC instead of 500 - @wolfgangwalther
+ - #1584, Fix RPC return type handling and embedding for domains with composite base type (#1615) - @wolfgangwalther
+ - #1608, #1635, Fix embedding through views that have COALESCE with subselect - @wolfgangwalther
+ - #1572, Fix parsing of boolean config values for Docker environment variables, now it accepts double quoted truth values ("true", "false") and numbers("1", "0") - @wolfgangwalther
+ - #1624, Fix using `app.settings.xxx` config options in Docker, now they can be used as `PGRST_APP_SETTINGS_xxx` - @wolfgangwalther
+ - #1814, Fix panic when attempting to run with unix socket on non-unix host and properly close unix domain socket on exit - @monacoremo
+ - #1825, Disregard internal junction(in non-exposed schema) when embedding - @steve-chavez
+ - #1846, Fix requests for overloaded functions from html forms to no longer hang (#1848) - @laurenceisla
+ - #1858, Add a hint and clarification to the no relationship found error - @laurenceisla
+ - #1841, Show comprehensive error when an RPC is not found in a stale schema cache - @laurenceisla
+ - #1875, Fix Location headers in headers only representation for null PK inserts on views - @laurenceisla
+
+### Changed
+
+ - #1522, #1528, #1535, Docker images are now built from scratch based on a the static PostgREST executable (#1494) and with Nix instead of a `Dockerfile`. This reduces the compressed image size from over 30mb to about 4mb - @monacoremo
+ - #1461, Location header for POST request is only included when PK is available on the table - @wolfgangwalther
+ - #1560, Volatile RPC called with GET now returns 405 Method not Allowed instead of 500 - @wolfgangwalther
+ - #1584, #1849 Functions that declare `returns composite_type` no longer return a single object array by default, only functions with `returns setof composite_type` return an array of objects - @wolfgangwalther
+ - #1604, Change the default logging level to `log-level=error`. Only requests with a status greater or equal than 500 will be logged. If you wish to go back to the previous behaviour and log all the requests, use `log-level=info` - @steve-chavez
+   + Because currently there's no buffering for logging, defaulting to the `error` level(minimum logging) increases throughput by around 15% for simple GET queries(no embedding, with filters applied).
+ - #1617, Dropped support for PostgreSQL 9.4 - @wolfgangwalther
+ - #1679, Renamed config settings with fallback aliases. e.g. `max-rows` is now `db-max-rows`, but `max-rows` is still accepted - @wolfgangwalther
+ - #1656, Allow `Prefer=headers-only` on POST requests and change default to `minimal` (#1813) - @laurenceisla
+ - #1854, Dropped undocumented support for gzip compression (which was surprisingly slow and easily enabled by mistake). In some use-cases this makes Postgres up to 3x faster - @aljungberg
+ - #1872, Send startup/worker logs to stderr to differentiate from access logs on stdout - @steve-chavez
+
+## [7.0.1] - 2020-05-18
+
+### Fixed
+
+- #1473, Fix overloaded computed columns on RPC - @wolfgangwalther
+- #1471, Fix POST, PATCH, DELETE with ?select= and return=minimal and PATCH with empty body - @wolfgangwalther
+- #1500, Fix missing `openapi-server-proxy-uri` config option - @steve-chavez
+- #1508, Fix `Content-Profile` not working for POST RPC - @steve-chavez
+- #1452, Fix PUT restriction for all columns - @steve-chavez
+
+### Changed
+
+- From this version onwards, the release page will only include a single Linux static executable that can be run on any Linux distribution.
+
+## [7.0.0] - 2020-04-03
+
+### Added
+
+- #1417, `Accept: application/vnd.pgrst.object+json` behavior is now enforced for POST/PATCH/DELETE regardless of `Prefer: return=representation/minimal` - @dwagin
+- #1415, Add support for user defined socket permission via `server-unix-socket-mode` config option - @Dansvidania
+- #1383, Add support for HEAD request - @steve-chavez
+- #1378, Add support for `Prefer: count=planned` and `Prefer: count=estimated` on GET /table - @steve-chavez, @LorenzHenk
+- #1327, Add support for optional query parameter `on_conflict` to upsert with specified keys for POST - @ykst
+- #1430, Allow specifying the foreign key constraint name(`/source?select=fk_constraint(*)`) to disambiguate an embedding - @steve-chavez
+- #1168, Allow access to the `Authorization` header through the `request.header.authorization` GUC - @steve-chavez
+- #1435, Add `request.method` and `request.path` GUCs - @steve-chavez
+- #1088, Allow adding headers to GET/POST/PATCH/PUT/DELETE responses through the `response.headers` GUC - @steve-chavez
+- #1427, Allow overriding provided headers(Location, Content-Type, etc) through the `response.headers` GUC - @steve-chavez
+- #1450, Allow multiple schemas to be exposed in one instance. The schema to use can be selected through the headers `Accept-Profile` for GET/HEAD and `Content-Profile` for POST/PATCH/PUT/DELETE - @steve-chavez, @mahmoudkassem
+
+### Fixed
+
+- #1301, Fix self join resource embedding on PATCH - @herulume, @steve-chavez
+- #1389, Fix many to many resource embedding on RPC/PATCH - @steve-chavez
+- #1355, Allow PATCH/DELETE without `return=minimal` on tables with no select privileges - @steve-chavez
+- #1361, Fix embedding a VIEW when its source foreign key is UNIQUE - @bwbroersma
+
+### Changed
+
+- #1385, bulk RPC call now should be done by specifying a `Prefer: params=multiple-objects` header - @steve-chavez
+- #1401, resource embedding now outputs an error when multiple relationships between two tables are found - @steve-chavez
+- #1423, default Unix Socket file mode from 755 to 660 - @dwagin
+- #1430, Remove embedding with duck typed column names `GET /projects?select=client(*)`- @steve-chavez
+  + You can rename the foreign key to `client` to make this request work in the new version: `alter table projects rename constraint projects_client_id_fkey to client`
+- #1413, Change `server-proxy-uri` config option to `openapi-server-proxy-uri` - @steve-chavez
+
+## [6.0.2] - 2019-08-22
+
+### Fixed
+
+- #1369, Change `raw-media-types` to accept a string of comma separated MIME types - @Dansvidania
+- #1368, Fix long column descriptions being truncated at 63 characters in PostgreSQL 12 - @amedeedaboville
+- #1348, Go back to converting plus "+" to space " " in querystrings by default - @steve-chavez
+
+### Deprecated
+
+- #1348, Deprecate `.` symbol for disambiguating resource embedding(added in #918). The url-safe '!' should be used instead. We refrained from using `+` as part of our syntax because it conflicts with some http clients and proxies.
+
+## [6.0.1] - 2019-07-30
+
+### Added
+
+- #1349, Add user defined raw output media types via `raw-media-types` config option - @Dansvidania
+- #1243, Add websearch_to_tsquery support - @herulume
+
+### Fixed
+
+- #1336, Error when testing on Chrome/Firefox: text/html requested but a single column was not selected - @Dansvidania
+- #1334, Unable to compile v6.0.0 on windows - @steve-chavez
+
+## [6.0.0] - 2019-06-21
+
+### Added
+
+- #1186, Add support for user defined unix socket via `server-unix-socket` config option - @Dansvidania
+- #690, Add `?columns` query parameter for faster bulk inserts, also ignores unspecified json keys in a payload - @steve-chavez
+- #1239, Add support for resource embedding on materialized views - @vitorbaptista
+- #1264, Add support for bulk RPC call - @steve-chavez
+- #1278, Add db-pool-timeout config option - @qu4tro
+- #1285, Abort on wrong database password - @qu4tro
+- #790, Allow override of OpenAPI spec through `root-spec` config option - @steve-chavez
+- #1308, Accept `text/plain` and `text/html` for raw output - @steve-chavez
+
+
+### Fixed
+
+- #1223, Fix incorrect OpenAPI externalDocs url - @steve-chavez
+- #1221, Fix embedding other resources when having a self join - @steve-chavez
+- #1242, Fix embedding a view having a select in a where - @steve-chavez
+- #1238, Fix PostgreSQL to OpenAPI type mappings for numeric and character types - @fpusch
+- #1265, Fix query generated on bulk upsert with an empty array - @qu4tro
+- #1273, Fix RPC ignoring unknown arguments by default - @steve-chavez
+- #1257, Fix incorrect status when a PATCH request doesn't find rows to change - @qu4tro
+
+### Changed
+
+- #1288, Change server-host default of 127.0.0.1 to !4
+
+### Deprecated
+
+- #1288, Deprecate `.` symbol for disambiguating resource embedding(added in #918). '+' should be used instead. Though '+' is url safe, certain clients might need to encode it to '%2B'.
+
+### Removed
+
+- #1288, Removed support for schema reloading with SIGHUP, SIGUSR1 should be used instead - @steve-chavez
+
+## [5.2.0] - 2018-12-12
+
+### Added
+
+- #1205, Add support for parsing JSON Web Key Sets - @russelldavies
+- #1203, Add support for reading db-uri from a separate file - @zhoufeng1989
+- #1200, Add db-extra-search-path config for adding schemas to the search_path, solves issues related to extensions created on the public schema - @steve-chavez
+- #1219, Add ability to quote column names on filters - @steve-chavez
+
+### Fixed
+
+- #1182, Fix embedding on views with composite pks - @steve-chavez
+- #1180, Fix embedding on views with subselects in pg10 - @steve-chavez
+- #1197, Allow CORS for PUT - @bkylerussell
+- #1181, Correctly qualify function argument of custom type in public schema - @steve-chavez
+- #1008, Allow columns that contain spaces in filters - @steve-chavez
+
+## [5.1.0] - 2018-08-31
+
+### Added
+
+- #1099, Add support for getting json/jsonb by array index - @steve-chavez
+- #1145, Add materialized view columns to OpenAPI output - @steve-chavez
+- #709, Allow embedding on views with subselects/CTE - @steve-chavez
+- #1148, OpenAPI: add `required` section for the non-nullable columns - @laughedelic
+- #1158, Add summary to OpenAPI doc for RPC functions - @mdr1384
+
+### Fixed
+
+- #1113, Fix UPSERT failing when having a camel case PK column - @steve-chavez
+- #945, Fix slow start-up time on big schemas - @steve-chavez
+- #1129, Fix view embedding when table is capitalized - @steve-chavez
+- #1149, OpenAPI: Change `GET` response type to array - @laughedelic
+- #1152, Fix RPC failing when having arguments with reserved or uppercase keywords - @mdr1384
+- #905, Fix intermittent empty replies - @steve-chavez
+- #1139, Fix JWTIssuedAtFuture failure for valid iat claim - @steve-chavez
+- #1141, Fix app.settings resetting on pool timeout - @steve-chavez
+
+### Changed
+
+- #1099, Numbers in json path `?select=data->1->>key` now get treated as json array indexes instead of keys - @steve-chavez
+- #1128, Allow finishing a json path with a single arrow `->`. Now a json can be obtained without resorting to casting, Previously: `/json_arr?select=data->>2::json`, now: `/json_arr?select=data->2` - @steve-chavez
+- #724, Change server-host default of *4 to 127.0.0.1
+
+### Deprecated
+
+- #724, SIGHUP deprecated, SIGUSR1 should be used instead
+
+## [0.5.0.0] - 2018-05-14
+
+### Added
+
+- The configuration (e.g. `postgrest.conf`) now accepts arbitrary settings that will be passed through as session-local database settings. This can be used to pass in secret keys directly as strings, or via OS environment variables. For instance: `app.settings.jwt_secret = "$(MYAPP_JWT_SECRET)"` will take `MYAPP_JWT_SECRET` from the environment and make it available to postgresql functions as `current_setting('app.settings.jwt_secret')`. Only `app.settings.*` values in the configuration file are treated in this way. - @canadaduane
+- #256, Add support for bulk UPSERT with POST and single UPSERT with PUT - @steve-chavez
+- #1078, Add ability to specify source column in embed - @steve-chavez
+- #821, Allow embeds alias to be used in filters - @steve-chavez
+- #906, Add jspath configurable `role-claim-key` - @steve-chavez
+- #1061, Add foreign tables to OpenAPI output - @rhyamada
+
+### Fixed
+
+- #828, Fix computed column only working in public schema - @steve-chavez
+- #925, Fix RPC high memory usage by using parametrized query and avoiding json encoding - @steve-chavez
+- #987, Fix embedding with self-reference foreign key - @steve-chavez
+- #1044, Fix view parent embedding when having many views - @steve-chavez
+- #781, Fix accepting misspelled desc/asc ordering modificators - @onporat, @steve-chavez
+
+### Changed
+
+- #828, A `SET SCHEMA <db-schema>` is done on each request, this has the following implications:
+  - Computed columns now only work if they belong to the db-schema
+  - Stored procedures might require a `search_path` to work properly, for further details see https://postgrest.org/en/v5.0/api.html#explicit-qualification
+- To use RPC now the `json_to_record/json_to_recordset` functions are needed, these are available starting from PostgreSQL 9.4 - @steve-chavez
+- Overloaded functions now depend on the `dbStructure`, restart/sighup may be needed for their correct functioning - @steve-chavez
+- #1098, Removed support for:
+  + curly braces `{}` in embeds, i.e. `/clients?select=*,projects{*}` can no longer be used, from now on parens `()` should be used `/clients?select=*,projects(*)` - @steve-chavez
+  + "in" operator without parens, i.e. `/clients?id=in.1,2,3` no longer supported, `/clients?id=in.(1,2,3)` should be used - @steve-chavez
+  + "@@", "@>" and "<@" operators, from now on their mnemonic equivalents should be used "fts", "cs" and "cd" respectively - @steve-chavez
+
+## [0.4.4.0] - 2018-01-08
+
+### Added
+
+- #887, #601, #1007, Allow specifying dictionary and plain/phrase tsquery in full text search - @steve-chavez
+- #328, Allow doing GET on rpc - @steve-chavez
+- #917, Add ability to map RAISE errorcode/message to http status - @steve-chavez
+- #940, Add ability to map GUC to http response headers - @steve-chavez
+- #1022, Include git sha in version report - @begriffs
+- Faster queries using json_agg - @ruslantalpa
+
+### Fixed
+
+- #876, Read secret files as binary, discard final LF if any - @eric-brechemier
+- #968, Treat blank proxy uri as missing - @begriffs
+- #933, OpenAPI externals docs url to current version - @steve-chavez
+- #962, OpenAPI don't err on nonexistent schema - @steve-chavez
+- #954, make OpenAPI rpc output dependent on user privileges - @steve-chavez
+- #955, Support configurable aud claim - @statik
+- #996, Fix embedded column conflicts table name - @grotsev
+- #974, Fix RPC error when function has single OUT param - @steve-chavez
+- #1021, Reduce join size in allColumns for faster program start - @nextstopsun
+- #411, Remove the need for pk in &select for parent embed - @steve-chavez
+- #1016, Fix anonymous requests when configured with jwt-aud - @ruslantalpa
+
 ## [0.4.3.0] - 2017-09-06
 
 ### Added

CODE_OF_CONDUCT.md

@@ -0,0 +1,132 @@
+
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, caste, color, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at support@postgrest.org.
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior,  harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+[https://www.contributor-covenant.org/version/2/0/code_of_conduct.html][v2.0].
+
+Community Impact Guidelines were inspired by
+[Mozilla's code of conduct enforcement ladder][Mozilla CoC].
+
+For answers to common questions about this code of conduct, see the FAQ at
+[https://www.contributor-covenant.org/faq][FAQ]. Translations are available
+at [https://www.contributor-covenant.org/translations][translations].
+
+[homepage]: https://www.contributor-covenant.org
+[v2.0]: https://www.contributor-covenant.org/version/2/0/code_of_conduct.html
+[Mozilla CoC]: https://github.com/mozilla/diversity
+[FAQ]: https://www.contributor-covenant.org/faq
+[translations]: https://www.contributor-covenant.org/translations

LICENSE

@@ -1,4 +1,5 @@
 Copyright (c) 2014 Joe Nelson
+Copyright (c) 2019 Steve Chavez
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

README.md

@@ -1,32 +1,83 @@
-![Logo](static/logo.png "Logo")
+![Logo](static/bigger-logo.png "Logo")
 
-[![Build Status](https://circleci.com/gh/begriffs/postgrest.png?style=shield&circle-token=f723c01686abf0364de1e2eaae5aff1f68bd3ff2)](https://circleci.com/gh/begriffs/postgrest/tree/master)
-<a href="https://heroku.com/deploy?template=https://github.com/begriffs/postgrest">
+[![Donate](https://img.shields.io/badge/Donate-Patreon-orange.svg?colorB=F96854)](https://www.patreon.com/postgrest)
+[![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.me/postgrest)
+<a href="https://heroku.com/deploy?template=https://github.com/PostgREST/postgrest">
   <img src="https://img.shields.io/badge/%E2%86%91_Deploy_to-Heroku-7056bf.svg" alt="Deploy">
 </a>
 [![Join the chat at https://gitter.im/begriffs/postgrest](https://img.shields.io/badge/gitter-join%20chat%20%E2%86%92-brightgreen.svg)](https://gitter.im/begriffs/postgrest)
-[![Docs](https://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat)](http://postgrest.com)
+[![Docs](https://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat)](http://postgrest.org)
+[![Docker Stars](https://img.shields.io/docker/pulls/postgrest/postgrest.svg)](https://hub.docker.com/r/postgrest/postgrest/)
+[![Build Status](https://circleci.com/gh/PostgREST/postgrest/tree/main.svg?style=shield)](https://circleci.com/gh/PostgREST/postgrest/tree/main)
+[![Coverage Status](https://img.shields.io/codecov/c/github/postgrest/postgrest/main)](https://app.codecov.io/gh/PostgREST/postgrest)
+[![Hackage docs](https://img.shields.io/hackage/v/postgrest.svg?label=hackage)](http://hackage.haskell.org/package/postgrest)
 
 PostgREST serves a fully RESTful API from any existing PostgreSQL
 database. It provides a cleaner, more standards-compliant, faster
 API than you are likely to write from scratch.
 
-### Usage
+## Sponsors
 
-1. Download the binary ([latest release](https://github.com/begriffs/postgrest/releases/latest))
+<table>
+  <tbody>
+    <tr>
+      <td align="center" valign="middle">
+        <a href="https://www.cybertec-postgresql.com/en/?utm_source=postgrest.org&utm_medium=referral&utm_campaign=postgrest" target="_blank">
+          <img width="222px" src="static/cybertec-new.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://www.2ndquadrant.com/en/?utm_campaign=External%20Websites&utm_source=PostgREST&utm_medium=Logo" target="_blank">
+          <img width="296px" src="static/2ndquadrant.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://tryretool.com/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="static/retool.png">
+        </a>
+      </td>
+    </tr>
+    <tr></tr>
+    <tr>
+      <td align="center" valign="middle">
+        <a href="https://gnuhost.eu/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="static/gnuhost.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://supabase.io?utm_source=postgrest%20backers&utm_medium=open%20source%20partner&utm_campaign=postgrest%20backers%20github&utm_term=homepage" target="_blank">
+          <img width="296px" src="static/supabase.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://oblivious.ai/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="static/oblivious.jpg">
+        </a>
+      </td>
+    </tr>
+  </tbody>
+</table>
+
+Big thanks to our sponsors! You can join them by supporting PostgREST on [Patreon](https://www.patreon.com/postgrest).
+
+## Usage
+
+1. Download the binary ([latest release](https://github.com/PostgREST/postgrest/releases/latest))
    for your platform.
 2. Invoke for help:
 
     ```bash
     postgrest --help
     ```
+## [Documentation](http://postgrest.org)
 
-### Performance
+Latest documentation is at [postgrest.org](http://postgrest.org). You can contribute to the docs in [PostgREST/postgrest-docs](https://github.com/PostgREST/postgrest-docs).
+
+## Performance
 
 TLDR; subsecond response times for up to 2000 requests/sec on Heroku
-free tier. If you're used to servers written in interpreted languages
-(or named after precious gems), prepare to be pleasantly surprised by
-PostgREST performance.
+free tier. If you're used to servers written in interpreted languages,
+prepare to be pleasantly surprised by PostgREST performance.
 
 Three factors contribute to the speed. First the server is written
 in [Haskell](https://www.haskell.org/) using the
@@ -49,13 +100,10 @@ by
 * Using the PostgreSQL binary protocol
 * Being stateless to allow horizontal scaling
 
-Other optimizations are possible, and some are outlined in the
-[Future Features](#future-features).
-
-### Security
+## Security
 
 PostgREST [handles
-authentication](http://postgrest.com/en/stable/auth.html) (via JSON Web
+authentication](http://postgrest.org/en/stable/auth.html) (via JSON Web
 Tokens) and delegates authorization to the role information defined in
 the database. This ensures there is a single declarative source of truth
 for security.  When dealing with the database the server assumes the
@@ -64,7 +112,7 @@ the connection cannot do anything the user themselves couldn't. Other
 forms of authentication can be built on top of the JWT primitive. See
 the docs for more information.
 
-PostgreSQL 9.5 supports true [row-level
+Since PostgreSQL 9.5 supports true [row-level
 security](http://www.postgresql.org/docs/9.5/static/ddl-rowsecurity.html).
 In previous versions it can be simulated with triggers and
 security-barrier views. Because the possible queries to the database
@@ -73,7 +121,7 @@ are limited to certain templates using
 functions, the trigger workaround does not compromise row-level
 security.
 
-### Versioning
+## Versioning
 
 A robust long-lived API needs the freedom to exist in multiple
 versions. PostgREST does versioning through database schemas. This
@@ -81,7 +129,7 @@ allows you to expose tables and views without making the app brittle.
 Underlying tables can be superseded and hidden behind public facing
 views.
 
-### Self-documentation
+## Self-documentation
 
 PostgREST uses the [OpenAPI](https://openapis.org/) standard to
 generate up-to-date documentation for APIs. You can use a tool like
@@ -93,7 +141,7 @@ instance the number of rows returned by an endpoint is reported by -
 and limited with - range headers. More about
 [that](http://begriffs.com/posts/2014-03-06-beyond-http-header-links.html).
 
-### Data Integrity
+## Data Integrity
 
 Rather than relying on an Object Relational Mapper and custom
 imperative coding, this system requires you put declarative constraints
@@ -105,14 +153,24 @@ surprises, such as enforcing idempotent PUT requests.
 
 See examples of [PostgreSQL
 constraints](http://www.tutorialspoint.com/postgresql/postgresql_constraints.htm)
-and the [API guide](http://postgrest.com/en/stable/api.html).
+and the [API guide](http://postgrest.org/en/stable/api.html).
 
-### Thanks
+## Supporting development
 
-I'm grateful to the generous project
-[contributors](https://github.com/begriffs/postgrest/graphs/contributors)
-who have improved PostgREST immensely with their code and good
-judgement.  See more details in the
-[changelog](https://github.com/begriffs/postgrest/blob/master/CHANGELOG.md).
+You can help PostgREST ongoing maintenance and development by:
+
+- Making a regular donation through Patreon https://www.patreon.com/postgrest
+
+- Alternatively, you can make a one-time donation via Paypal https://www.paypal.me/postgrest
+
+Every donation will be spent on making PostgREST better for the whole community.
+
+## Thanks
+
+The PostgREST organization is grateful to:
+
+- The project [sponsors and backers](https://github.com/PostgREST/postgrest/blob/main/BACKERS.md) who support PostgREST's development.
+- The project [contributors](https://github.com/PostgREST/postgrest/graphs/contributors) who have improved PostgREST immensely with their code
+  and good judgement. See more details in the [changelog](https://github.com/PostgREST/postgrest/blob/main/CHANGELOG.md).
 
 The cool logo came from [Mikey Casalaina](https://github.com/casalaina).

Setup.hs

@@ -1,2 +1,3 @@
+-- This file is required by Hackage.
 import Distribution.Simple
 main = defaultMain

app.json

@@ -1,19 +1,19 @@
 {
   "name": "PostgREST",
   "description": "RESTful API for any PostgreSQL database.",
-  "logo": "https://halcyon.sh/logo.svg",
-  "repository": "https://github.com/begriffs/postgrest",
+  "logo": "https://avatars2.githubusercontent.com/u/15115011",
+  "repository": "https://github.com/PostgREST/postgrest",
   "env": {
     "BUILDPACK_URL": {
       "description": "Heroku buildpack for deploying Haskell applications",
-      "value": "https://github.com/begriffs/postgrest-heroku"
+      "value": "https://github.com/PostgREST/postgrest-heroku"
     },
     "POSTGREST_VER": {
       "description": "Version of PostgREST to deploy",
-      "value": "0.4.3.0"
+      "value": "8.0.0"
     },
     "DB_URI": {
-      "description": "Database connection string",
+      "description": "Database connection string, e.g. postgres://user:pass@xxxxxxx.rds.amazonaws.com/mydb",
       "required": true
     },
     "DB_SCHEMA": {
@@ -43,6 +43,10 @@
       "required": false,
       "value": "false"
     },
+    "JWT_AUD": {
+      "description": "The audience that should be validated if the JWT token contains an aud claim",
+      "required": false
+    },
     "MAX_ROWS": {
       "description": "A hard limit to the number of rows PostgREST will fetch from a view, table, or stored procedure",
       "required": false

appveyor.yml

@@ -1,24 +1,20 @@
+## AppVeyor is only used for building a Windows binary, no tests are run here.
 platform: x64
+image: Visual Studio 2015
 
 cache:
 - "c:\\sr"
 - .stack-work
+- "c:\\Users\\appveyor\\AppData\\Local\\Programs\\stack"
 
 environment:
   global:
     STACK_ROOT: "c:\\sr"
     GOPATH: c:\gopath
+    TMP: "c:\\tmp"
 
 test: off
 
-skip_non_tags: true
-
-skip_branch_with_pr: true
-
-branches:
-  only:
-    - master
-
 install:
 - set PATH=C:\Program Files\PostgreSQL\9.6\bin\;%PATH%
 - curl -sS -ostack.zip -L --insecure http://www.stackage.org/stack/windows-x86_64
@@ -27,12 +23,25 @@ install:
 - go get -u github.com/tcnksm/ghr
 
 build_script:
+- ps: $env:cabal_nightly_version=(git show -s --format='%cd' --date='format:%Y%m%d')
+- IF "%APPVEYOR_REPO_TAG_NAME%"=="nightly" bash -lc "sed -i -r \"s/^(version:\s+)\S+$/\1$cabal_nightly_version/\" postgrest.cabal"
 - stack setup --no-terminal > nul
-- stack build --copy-bins --local-bin-path .
+# Appveyor has a timeout of 60 mins, building can take longer, limit the time and make sure this succeeds,
+# previous work will get cached and finish on next commit
+- bash -lc "timeout 2700 'C:\projects\postgrest\stack.exe' build -j1 --copy-bins --local-bin-path . || (($?==124))"
 
 artifacts:
 - path: postgrest.exe
 
 deploy_script:
-- 7z a -tzip postgrest-%APPVEYOR_REPO_TAG_NAME%-windows-x64.zip postgrest.exe
-- bash -lc "exec 0</dev/null && cd $APPVEYOR_BUILD_FOLDER && ghr -t $GITHUB_TOKEN -u $APPVEYOR_ACCOUNT_NAME -r $APPVEYOR_PROJECT_NAME -b \"$(sed -n \"1,/$(echo $APPVEYOR_REPO_TAG_NAME | cut -c2-)/d;/## \[/q;p\" CHANGELOG.md)\" --replace $APPVEYOR_REPO_TAG_NAME postgrest-$APPVEYOR_REPO_TAG_NAME-windows-x64.zip"
+## Use powershell(ps) for this because CMD commands having "%" don't work(even by escaping with "%%"). See https://github.com/appveyor/ci/issues/246.
+- ps: $env:suffix=(git show -s --format="%cd-%h" --date="format:%Y-%m-%d-%H-%M")
+- IF DEFINED APPVEYOR_REPO_TAG_NAME (
+    IF "%APPVEYOR_REPO_TAG_NAME%"=="nightly" (
+      7z a -tzip postgrest-nightly-%suffix%-windows-x64.zip postgrest.exe &&
+      bash -lc "exec 0</dev/null && cd $APPVEYOR_BUILD_FOLDER && ghr -t $GITHUB_TOKEN -u $APPVEYOR_ACCOUNT_NAME -r $APPVEYOR_PROJECT_NAME --replace nightly postgrest-nightly-$suffix-windows-x64.zip"
+    ) ELSE (
+      7z a -tzip postgrest-%APPVEYOR_REPO_TAG_NAME%-windows-x64.zip postgrest.exe &&
+      bash -lc "exec 0</dev/null && cd $APPVEYOR_BUILD_FOLDER && ghr -t $GITHUB_TOKEN -u $APPVEYOR_ACCOUNT_NAME -r $APPVEYOR_PROJECT_NAME -b \"`sed -n \"1,/$APPVEYOR_REPO_TAG_NAME/d;/## \[/q;p\" CHANGELOG.md`\" --replace $APPVEYOR_REPO_TAG_NAME postgrest-$APPVEYOR_REPO_TAG_NAME-windows-x64.zip"
+    )
+  )

default.nix

@@ -0,0 +1,157 @@
+let
+  name =
+    "postgrest";
+
+  compiler =
+    "ghc8104";
+
+  # PostgREST source files, filtered based on the rules in the .gitignore files
+  # and file extensions. We want to include as litte as possible, as the files
+  # added here will increase the space used in the Nix store and trigger the
+  # build of new Nix derivations when changed.
+  src =
+    pkgs.lib.sourceFilesBySuffices
+      (pkgs.gitignoreSource ./.)
+      [ ".cabal" ".hs" ".lhs" "LICENSE" ];
+
+  # Commit of the Nixpkgs repository that we want to use.
+  nixpkgsVersion =
+    import nix/nixpkgs-version.nix;
+
+  # Nix files that describe the Nixpkgs repository. We evaluate the expression
+  # using `import` below.
+  nixpkgs =
+    builtins.fetchTarball {
+      url = "https://github.com/nixos/nixpkgs/archive/${nixpkgsVersion.rev}.tar.gz";
+      sha256 = nixpkgsVersion.tarballHash;
+    };
+
+  allOverlays =
+    import nix/overlays;
+
+  overlays =
+    [
+      allOverlays.build-toolbox
+      allOverlays.checked-shell-script
+      allOverlays.ghr
+      allOverlays.gitignore
+      allOverlays.postgresql-default
+      allOverlays.postgresql-legacy
+      (allOverlays.haskell-packages { inherit compiler; })
+    ];
+
+  # Evaluated expression of the Nixpkgs repository.
+  pkgs =
+    import nixpkgs { inherit overlays; };
+
+  postgresqlVersions =
+    [
+      { name = "postgresql-13"; postgresql = pkgs.postgresql_13; }
+      { name = "postgresql-12"; postgresql = pkgs.postgresql_12; }
+      { name = "postgresql-11"; postgresql = pkgs.postgresql_11; }
+      { name = "postgresql-10"; postgresql = pkgs.postgresql_10; }
+      { name = "postgresql-9.6"; postgresql = pkgs.postgresql_9_6; }
+      { name = "postgresql-9.5"; postgresql = pkgs.postgresql_9_5; }
+    ];
+
+  patches =
+    pkgs.callPackage nix/patches { };
+
+  # Dynamic derivation for PostgREST
+  postgrest =
+    pkgs.haskell.packages."${compiler}".callCabal2nix name src { };
+
+  # Function that derives a fully static Haskell package based on
+  # nh2/static-haskell-nix
+  staticHaskellPackage =
+    import nix/static-haskell-package.nix { inherit nixpkgs compiler patches allOverlays; };
+
+  # Options passed to cabal in dev tools and tests
+  devCabalOptions =
+    "-f dev --test-show-detail=direct";
+
+  profiledHaskellPackages =
+    pkgs.haskell.packages."${compiler}".extend (self: super:
+      {
+        mkDerivation =
+          args:
+          super.mkDerivation (args // { enableLibraryProfiling = true; });
+      }
+    );
+
+  lib =
+    pkgs.haskell.lib;
+in
+rec {
+  inherit nixpkgs pkgs;
+
+  # Derivation for the PostgREST Haskell package, including the executable,
+  # libraries and documentation. We disable running the test suite on Nix
+  # builds, as they require a database to be set up.
+  postgrestPackage =
+    lib.dontCheck postgrest;
+
+  # Static executable.
+  postgrestStatic =
+    lib.justStaticExecutables (lib.dontCheck (staticHaskellPackage name src));
+
+  # Profiled dynamic executable.
+  postgrestProfiled =
+    lib.enableExecutableProfiling (
+      lib.dontHaddock (
+        lib.dontCheck (profiledHaskellPackages.callCabal2nix name src { })
+      )
+    );
+
+  env =
+    postgrest.env;
+
+  # Tooling for analyzing Haskell imports and exports.
+  hsie =
+    pkgs.callPackage nix/hsie {
+      ghcWithPackages = pkgs.haskell.packages.ghc884.ghcWithPackages;
+    };
+
+  ### Tools
+
+  cabalTools =
+    pkgs.callPackage nix/tools/cabalTools.nix { inherit devCabalOptions postgrest; };
+
+  # Development tools.
+  devTools =
+    pkgs.callPackage nix/tools/devTools.nix { inherit tests style devCabalOptions hsie; };
+
+  # Docker images and loading script.
+  docker =
+    pkgs.callPackage nix/tools/docker { postgrest = postgrestStatic; };
+
+  # Script for running memory tests.
+  memory =
+    pkgs.callPackage nix/tools/memory.nix { inherit postgrestProfiled withTools; };
+
+  # Utility for updating the pinned version of Nixpkgs.
+  nixpkgsTools =
+    pkgs.callPackage nix/tools/nixpkgsTools.nix { };
+
+  # Scripts for publishing new releases.
+  release =
+    pkgs.callPackage nix/tools/release {
+      inherit docker;
+      postgrest = postgrestStatic;
+    };
+
+  # Linting and styling tools.
+  style =
+    pkgs.callPackage nix/tools/style.nix { };
+
+  # Scripts for running tests.
+  tests =
+    pkgs.callPackage nix/tools/tests.nix {
+      inherit postgrest devCabalOptions withTools;
+      ghc = pkgs.haskell.compiler."${compiler}";
+      hpc-codecov = pkgs.haskell.packages."${compiler}".hpc-codecov;
+    };
+
+  withTools =
+    pkgs.callPackage nix/tools/withTools.nix { inherit postgresqlVersions; };
+}

docker/Dockerfile

@@ -1,43 +0,0 @@
-FROM debian:jessie
-
-ARG POSTGREST_VERSION
-
-# Install libpq5
-RUN apt-get -qq update && \
-    apt-get -qq install -y --no-install-recommends libpq5 && \
-    apt-get -qq clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# Install postgrest
-RUN BUILD_DEPS="curl ca-certificates xz-utils" && \
-    apt-get -qq update && \
-    apt-get -qq install -y --no-install-recommends $BUILD_DEPS && \
-    cd /tmp && \
-    curl -SLO https://github.com/begriffs/postgrest/releases/download/${POSTGREST_VERSION}/postgrest-${POSTGREST_VERSION}-ubuntu.tar.xz && \
-    tar -xJvf postgrest-${POSTGREST_VERSION}-ubuntu.tar.xz && \
-    mv postgrest /usr/local/bin/postgrest && \
-    cd / && \
-    apt-get -qq purge --auto-remove -y $BUILD_DEPS && \
-    apt-get -qq clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-COPY postgrest.conf /etc/postgrest.conf
-
-
-ENV PGRST_DB_URI= \
-    PGRST_DB_SCHEMA=public \
-    PGRST_DB_ANON_ROLE= \
-    PGRST_DB_POOL=100 \
-    PGRST_SERVER_HOST=*4 \
-    PGRST_SERVER_PORT=3000 \
-    PGRST_SERVER_PROXY_URL= \
-    PGRST_JWT_SECRET= \
-    PGRST_SECRET_IS_BASE64=false \
-    PGRST_MAX_ROWS= \
-    PGRST_PRE_REQUEST=
-
-# PostgREST reads /etc/postgrest.conf so map the configuration
-# file in when you run this container
-CMD exec postgrest /etc/postgrest.conf
-
-EXPOSE 3000

docker/config.conf

@@ -1,3 +0,0 @@
-db-uri = "postgres://app_user:password@postgres:5432/app_db"
-db-schema = "public"
-db-anon-role = "app_user"

docker/distro_release/Dockerfile.centos6

@@ -1,18 +0,0 @@
-FROM centos:centos6
-
-RUN yum -y update
-RUN yum -y install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar
-RUN yum -y install https://download.postgresql.org/pub/repos/yum/9.3/redhat/rhel-6-x86_64/pgdg-centos93-9.3-2.noarch.rpm
-RUN yum -y install postgresql93-devel
-RUN yum clean all
-RUN curl -sSL https://get.haskellstack.org/ | sh
-
-ENV PATH $PATH:/usr/pgsql-9.3/bin
-
-# To disable warning when building
-ENV PATH $PATH:/root/.local/bin
-
-RUN mkdir /source
-WORKDIR /source
-
-ENTRYPOINT ["stack"]

docker/distro_release/Dockerfile.centos7

@@ -1,18 +0,0 @@
-FROM centos:centos7
-
-RUN yum -y update
-RUN yum -y install perl make automake gcc gmp-devel libffi zlib zlib-devel xz tar
-RUN yum -y install yum install https://download.postgresql.org/pub/repos/yum/9.3/redhat/rhel-7-x86_64/pgdg-centos93-9.3-2.noarch.rpm
-RUN yum -y install postgresql93-devel
-RUN yum clean all
-RUN curl -sSL https://get.haskellstack.org/ | sh
-
-ENV PATH $PATH:/usr/pgsql-9.3/bin
-
-# To disable warning when building
-ENV PATH $PATH:/root/.local/bin
-
-RUN mkdir /source
-WORKDIR /source
-
-ENTRYPOINT ["stack"]

docker/distro_release/Dockerfile.ubuntu

@@ -1,18 +0,0 @@
-FROM ubuntu:16.04
-
-RUN BUILD_DEPS="curl ca-certificates build-essential" && \
-    apt-get -qq update && \
-    apt-get -qqy --no-install-recommends install \
-    $BUILD_DEPS \
-    libpq-dev && \
-    curl -sSL https://get.haskellstack.org/ | sh && \
-    apt-get -qq clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# To disable warning when building
-ENV PATH $PATH:/root/.local/bin
-
-RUN mkdir /source
-WORKDIR /source
-
-ENTRYPOINT ["stack"]

docker/distro_release/Dockerfile.ubuntui386

@@ -1,18 +0,0 @@
-FROM 32bit/ubuntu:16.04
-
-RUN BUILD_DEPS="curl ca-certificates build-essential" && \
-    apt-get -qq update && \
-    apt-get -qqy --no-install-recommends install \
-    $BUILD_DEPS \
-    libpq-dev && \
-    curl -sSL https://get.haskellstack.org/ | sh && \
-    apt-get -qq clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# To disable warning when building
-ENV PATH $PATH:/root/.local/bin
-
-RUN mkdir /source
-WORKDIR /source
-
-ENTRYPOINT ["stack"]

docker/docker-compose.yml

@@ -1,19 +0,0 @@
-stgrest:
-  image: pg_local
-  ports:
-    - "3000:3000"
-  links:
-    - postgres:postgres
-  environment:
-    PGRST_DB_URI: postgres://app_user:password@postgres:5432/app_db
-    PGRST_DB_SCHEMA: public
-    PGRST_DB_ANON_ROLE: app_user
-
-postgres:
-  image: postgres
-  ports:
-    - "5432:5432"
-  environment:
-    POSTGRES_DB: app_db
-    POSTGRES_USER: app_user
-    POSTGRES_PASSWORD: password

docker/postgrest.conf

@@ -1,14 +0,0 @@
-db-uri = "$(PGRST_DB_URI)"
-db-schema = "$(PGRST_DB_SCHEMA)"
-db-anon-role = "$(PGRST_DB_ANON_ROLE)"
-db-pool = "$(PGRST_DB_POOL)"
-
-server-host = "$(PGRST_SERVER_HOST)"
-server-port = "$(PGRST_SERVER_PORT)"
-
-server-proxy-uri = "$(PGRST_SERVER_PROXY_URI)"
-jwt-secret = "$(PGRST_JWT_SECRET)"
-secret-is-base64 = "$(PGRST_SECRET_IS_BASE64)"
-
-max-rows = "$(PGRST_MAX_ROWS)"
-pre-request = "$(PGRST_PRE_REQUEST)"

main/Main.hs

@@ -1,281 +1,47 @@
 {-# LANGUAGE CPP #-}
 
-module Main where
+module Main (main) where
 
-import           PostgREST.App            (postgrest)
-import           PostgREST.Config         (AppConfig (..),
-                                           PgVersion (..),
-                                           minimumPgVersion,
-                                           prettyVersion, readOptions)
-import           PostgREST.DbStructure    (getDbStructure)
-import           PostgREST.Error          (encodeError)
-import           PostgREST.OpenAPI        (isMalformedProxyUri)
-import           PostgREST.Types          (DbStructure, Schema)
-import           Protolude hiding         (replace, hPutStrLn)
+import qualified Data.Map.Strict as M
+
+import System.IO (BufferMode (..), hSetBuffering)
+
+import qualified PostgREST.App as App
+import qualified PostgREST.CLI as CLI
+
+import PostgREST.Config (readPGRSTEnvironment)
+
+import Protolude
 
-import           Control.Retry            (RetryStatus, capDelay,
-                                           exponentialBackoff,
-                                           retrying, rsPreviousDelay)
-import           Data.ByteString.Base64   (decode)
-import           Data.IORef               (IORef, atomicWriteIORef,
-                                           newIORef, readIORef)
-import           Data.String              (IsString (..))
-import           Data.Text                (pack, replace, stripPrefix, strip)
-import           Data.Text.Encoding       (decodeUtf8, encodeUtf8)
-import           Data.Text.IO             (hPutStrLn, readFile)
-import qualified Hasql.Decoders           as HD
-import qualified Hasql.Encoders           as HE
-import qualified Hasql.Pool               as P
-import qualified Hasql.Query              as H
-import qualified Hasql.Session            as H
-import           Network.Wai.Handler.Warp (defaultSettings,
-                                           runSettings, setHost,
-                                           setPort, setServerName,
-                                           setTimeout)
-import           System.IO                (BufferMode (..),
-                                           hSetBuffering)
 #ifndef mingw32_HOST_OS
-import           System.Posix.Signals
+import qualified PostgREST.Unix as Unix
 #endif
 
-{-|
-	Used by connectionWorker to know if it should throw an error and kill the
-  main thread.
--}
-isServerVersionSupported :: H.Session Bool
-isServerVersionSupported = do
-  ver <- H.query () pgVersion
-  return $ ver >= pgvNum minimumPgVersion
- where
-  pgVersion =
-    H.statement "SELECT current_setting('server_version_num')::integer"
-      HE.unit (HD.singleRow $ HD.value HD.int4) False
-
-{-|
-  The purpose of this worker is to fill the refDbStructure created in 'main'
-  with the 'DbStructure' returned from calling 'getDbStructure'. This method
-  is meant to be called by multiple times by the same thread, but does nothing if
-  the previous invocation has not terminated. In all cases this method does not
-  halt the calling thread, the work is preformed in a separate thread.
-
-  Note: 'atomicWriteIORef' is essentially a lazy semaphore that prevents two
-  threads from running 'connectionWorker' at the same time.
-
-  Background thread that does the following :
-  1. Tries to connect to pg server and will keep trying until success.
-  2. Checks if the pg version is supported and if it's not it kills the main
-     program.
-  3. Obtains the dbStructure.
-  4. If 2 or 3 fail to give their result it means the connection is down so it
-     goes back to 1, otherwise it finishes his work successfully.
--}
-connectionWorker
-  :: ThreadId -- ^ This thread is killed if 'isServerVersionSupported' returns false
-  -> P.Pool   -- ^ The PostgreSQL connection pool
-  -> Schema   -- ^ Schema PostgREST is serving up
-  -> IORef (Maybe DbStructure) -- ^ mutable reference to 'DbStructure'
-  -> IORef Bool                -- ^ Used as a binary Semaphore
-  -> IO ()
-connectionWorker mainTid pool schema refDbStructure refIsWorkerOn = do
-  isWorkerOn <- readIORef refIsWorkerOn
-  unless isWorkerOn $ do
-    atomicWriteIORef refIsWorkerOn True
-    void $ forkIO work
-  where
-    work = do
-      atomicWriteIORef refDbStructure Nothing
-      putStrLn ("Attempting to connect to the database..." :: Text)
-      connected <- connectingSucceeded pool
-      when connected $ do
-        result <- P.use pool $ do
-          supported <- isServerVersionSupported
-          unless supported $ liftIO $ do
-            hPutStrLn stderr
-              ("Cannot run in this PostgreSQL version, PostgREST needs at least "
-              <> pgvName minimumPgVersion)
-            killThread mainTid
-          dbStructure <- getDbStructure schema
-          liftIO $ atomicWriteIORef refDbStructure $ Just dbStructure
-        case result of
-          Left e -> do
-            putStrLn ("Failed to query the database. Retrying." :: Text)
-            hPutStrLn stderr (toS $ encodeError e)
-            work
-          Right _ -> do
-            atomicWriteIORef refIsWorkerOn False
-            putStrLn ("Connection successful" :: Text)
-
-
-{-|
-  Used by 'connectionWorker' to check if the provided db-uri lets
-  the application access the PostgreSQL database. This method is used
-  the first time the connection is tested, but only to test before
-  calling 'getDbStructure' inside the 'connectionWorker' method.
-
-  The connection tries are capped, but if the connection times out no error is
-  thrown, just 'False' is returned.
--}
-connectingSucceeded :: P.Pool -> IO Bool
-connectingSucceeded pool =
-  retrying (capDelay 32000000 $ exponentialBackoff 1000000)
-           shouldRetry
-           (const $ P.release pool >> isConnectionSuccessful)
-  where
-    isConnectionSuccessful :: IO Bool
-    isConnectionSuccessful = do
-      testConn <- P.use pool $ H.sql "SELECT 1"
-      case testConn of
-        Left e -> hPutStrLn stderr (toS $ encodeError e) >> pure False
-        _ -> pure True
-    shouldRetry :: RetryStatus -> Bool -> IO Bool
-    shouldRetry rs isConnSucc = do
-      delay <- pure $ fromMaybe 0 (rsPreviousDelay rs) `div` 1000000
-      itShould <- pure $ not isConnSucc
-      when itShould $
-        putStrLn $ "Attempting to reconnect to the database in " <> (show delay::Text) <> " seconds..."
-      return itShould
-
-{-|
-  This is where everything starts.
--}
 main :: IO ()
 main = do
-  --
-  -- LineBuffering: the entire output buffer is flushed whenever a newline is
-  -- output, the buffer overflows, a hFlush is issued or the handle is closed
-  --
-  -- NoBuffering: output is written immediately and never stored in the buffer
-  hSetBuffering stdout LineBuffering
-  hSetBuffering stdin LineBuffering
-  hSetBuffering stderr NoBuffering
-  --
-  -- readOptions builds the 'AppConfig' from the config file specified on the
-  -- command line
-  conf <- loadSecretFile =<< readOptions
-  let host = configHost conf
-      port = configPort conf
-      proxy = configProxyUri conf
-      pgSettings = toS (configDatabase conf) -- is the db-uri
-      appSettings =
-        setHost ((fromString . toS) host) -- Warp settings
-        . setPort port
-        . setServerName (toS $ "postgrest/" <> prettyVersion)
-        . setTimeout 3600 $
-        defaultSettings
-  --
-  -- Checks that the provided proxy uri is formated correctly,
-  -- does not test if it works here.
-  when (isMalformedProxyUri $ toS <$> proxy) $
-    panic
-      "Malformed proxy uri, a correct example: https://example.com:8443/basePath"
-  putStrLn $ ("Listening on port " :: Text) <> show (configPort conf)
-  --
-  -- create connection pool with the provided settings, returns either
-  -- a 'Connection' or a 'ConnectionError'. Does not throw.
-  pool <- P.acquire (configPool conf, 10, pgSettings)
-  --
-  -- To be filled in by connectionWorker
-  refDbStructure <- newIORef Nothing
-  --
-  -- Helper ref to make sure just one connectionWorker can run at a time
-  refIsWorkerOn <- newIORef False
-  --
-  -- This is passed to the connectionWorker method so it can kill the main
-  -- thread if the PostgreSQL's version is not supported.
-  mainTid <- myThreadId
-  --
-  -- Sets the refDbStructure
-  connectionWorker
-    mainTid
-    pool
-    (configSchema conf)
-    refDbStructure
-    refIsWorkerOn
-  --
-  -- Only for systems with signals:
-  --
-  -- releases the connection pool whenever the program is terminated,
-  -- see issue #268
-  --
-  -- Plus the SIGHUP signal updates the internal 'DbStructure' by running
-  -- 'connectionWorker' exactly as before.
-#ifndef mingw32_HOST_OS
-  forM_ [sigINT, sigTERM] $ \sig ->
-    void $ installHandler sig (Catch $ do
-        P.release pool
-        throwTo mainTid UserInterrupt
-      ) Nothing
+  setBuffering
+  hasPGRSTEnv <- not . M.null <$> readPGRSTEnvironment
+  opts <- CLI.readCLIShowHelp hasPGRSTEnv
+  CLI.main installSignalHandlers runAppInSocket opts
 
-  void $ installHandler sigHUP (
-    Catch $ connectionWorker
-              mainTid
-              pool
-              (configSchema conf)
-              refDbStructure
-              refIsWorkerOn
-    ) Nothing
+installSignalHandlers :: App.SignalHandlerInstaller
+#ifndef mingw32_HOST_OS
+installSignalHandlers = Unix.installSignalHandlers
+#else
+installSignalHandlers _ = pass
 #endif
 
-  --
-  -- run the postgrest application
-  runSettings appSettings $
-    postgrest
-      conf
-      refDbStructure
-      pool
-      (connectionWorker
-         mainTid
-         pool
-         (configSchema conf)
-         refDbStructure
-         refIsWorkerOn)
+runAppInSocket :: Maybe App.SocketRunner
+#ifndef mingw32_HOST_OS
+runAppInSocket = Just Unix.runAppWithSocket
+#else
+runAppInSocket = Nothing
+#endif
 
-{-|
-  The purpose of this function is to load the JWT secret from a file if
-  configJwtSecret is actually a filepath and replaces some characters if the JWT
-  is base64 encoded.
-
-  The reason some characters need to be replaced is because JWT is actually
-  base64url encoded which must be turned into just base64 before decoding.
-
-  To check if the JWT secret is provided is in fact a file path, it must be
-  decoded as 'Text' to be processed.
-
-  decodeUtf8: Decode a ByteString containing UTF-8 encoded text that is known to
-  be valid.
--}
-loadSecretFile :: AppConfig -> IO AppConfig
-loadSecretFile conf = extractAndTransform mSecret
-  where
-    mSecret = decodeUtf8 <$> configJwtSecret conf
-    isB64 = configJwtSecretIsBase64 conf
-    --
-    -- The Text (variable name secret) here is mSecret from above which is the JWT
-    -- decoded as Utf8
-    --
-    -- stripPrefix: Return the suffix of the second string if its prefix matches
-    -- the entire first string.
-    --
-    -- The configJwtSecret is a filepath instead of the JWT secret itself if the
-    -- secret has @ as its prefix.
-    extractAndTransform :: Maybe Text -> IO AppConfig
-    extractAndTransform Nothing = return conf
-    extractAndTransform (Just secret) =
-      fmap setSecret $
-      transformString isB64 =<<
-      case stripPrefix "@" secret of
-        Nothing       -> return secret
-        Just filename -> readFile (toS filename)
-    --
-    -- Turns the Base64url encoded JWT into Base64
-    transformString :: Bool -> Text -> IO ByteString
-    transformString False t = return . encodeUtf8 $ t
-    transformString True t =
-      case decode (encodeUtf8 $ strip $ replaceUrlChars t) of
-        Left errMsg -> panic $ pack errMsg
-        Right bs    -> return bs
-    setSecret bs = conf {configJwtSecret = Just bs}
-    --
-    -- replace: Replace every occurrence of one substring with another
-    replaceUrlChars =
-      replace "_" "/" . replace "-" "+" . replace "." "="
+setBuffering :: IO ()
+setBuffering = do
+  -- LineBuffering: the entire output buffer is flushed whenever a newline is
+  -- output, the buffer overflows, a hFlush is issued or the handle is closed
+  hSetBuffering stdout LineBuffering
+  hSetBuffering stdin LineBuffering
+  hSetBuffering stderr LineBuffering

nix/Dockerfile

@@ -0,0 +1,22 @@
+# This Dockerfile is only used as a development environment for
+# non-nix systems, i.e. Windows.
+
+FROM nixos/nix:latest
+
+RUN apk --no-cache add \
+    wget
+
+RUN nix-env -iA cachix -f https://cachix.org/api/v1/install \
+ && cachix use postgrest
+
+# We need an unprivileged user here, to make PG run at all.
+RUN adduser --disabled-password --ingroup root nix \
+ && chown -R nix:root /nix
+USER nix:root
+ENV USER=nix
+
+VOLUME /nix
+VOLUME /postgrest
+WORKDIR /postgrest
+
+CMD nix-shell

nix/README.md

@@ -0,0 +1,260 @@
+# Nix development and build environment
+
+With Nix it's possible to quickly and reliably recreate the full environments
+for developing, testing and building PostgREST.
+
+## Getting started with Nix
+
+You'll need to [get Nix](https://nixos.org/download.html). The installer will
+create your Nix store in the `/nix/` directory, where all build artifacts and
+their dependencies will be stored. It will also link the Nix executables like
+`nix-env`, `nix-build` and `nix-shell` into your PATH. Nix will manage all
+other PostgREST dependencies from here on out. To clean up older build
+artifacts from the `/nix/store`, you can run `nix-collect-garbage`.
+
+If you are on a system that does not support nix, for example Windows, you can
+run the nix development environment in a docker container. Inside the `nix/`
+directory run `docker-compose run --rm nix` to start the docker container. This
+will set up the binary cache and launch `nix-shell` automatically.
+
+## Building PostgREST
+
+To build PostgREST from your local checkout of the repository, run:
+
+```bash
+nix-build --attr postgrestPackage
+
+```
+
+This will create a `result` directory that contains the PostgREST binary at
+`result/bin/postgrest`. The `--attr` parameter (or short: `-A`) tells Nix to
+build the `postgrestPackage` attribute from the Nix expression it finds in our
+`default.nix` (see below for details). Nix will take care of getting the right
+GHC version and all the build dependencies.
+
+## Binary cache
+
+We recommend that you use the PostgREST binary cache on
+[cachix](https://cachix.org/):
+
+```bash
+# Install cachix:
+nix-env -iA cachix -f https://cachix.org/api/v1/install
+
+# Set cachix up to use the PostgREST binary cache:
+cachix use postgrest
+
+```
+
+Without cachix, your machine will have to rebuild all the dependencies that are
+derived on top of `Musl` for the static builds, which can take a very long time.
+
+## Developing
+
+A development environment for PostgREST is available with `nix-shell`. The
+following command will put you into a new shell that has GHC and Cabal on the
+PATH:
+
+```bash
+nix-shell
+
+```
+
+Within `nix-shell`, you can run Cabal commands as usual. You can also run
+stack with the `--nix` option, which causes stack to pick up the non-Haskell
+dependencies from the same pinned Nixpkgs version that the Nix builds use.
+
+## Working with `nix-shell` and the PostgREST utility scripts
+
+The PostgREST utilities available in `nix-shell` all have names that begin with
+`postgrest-`, so you can use tab completion (typing `postgrest-` and pressing
+`<tab>`) in `nix-shell` to see all that are available:
+
+```bash
+# Note: The utilities listed here might not be up to date.
+[nix-shell]$ postgrest-<tab>
+postgrest-build                   postgrest-test-spec
+postgrest-check                   postgrest-watch
+postgrest-clean                   postgrest-with-all
+postgrest-coverage                postgrest-with-postgresql-10
+postgrest-lint                    postgrest-with-postgresql-11
+postgrest-run                     postgrest-with-postgresql-12
+postgrest-style                   postgrest-with-postgresql-13
+postgrest-style-check             postgrest-with-postgresql-9.5
+postgrest-test-io                 postgrest-with-postgresql-9.6
+...
+
+[nix-shell]$
+
+```
+
+Some additional modules like `memory`, `docker` and `release`
+have large dependencies that would need to be built before the shell becomes
+available, which could take an especially long time if the cachix binary cache
+is not used. You can activate those by passing a flag to `nix-shell` with
+`nix-shell --arg <module> true`. This will make the respective utilites available:
+
+```bash
+$ nix-shell --arg memory true
+[nix-shell]$ postgrest-<tab>
+postgrest-build                   postgrest-test-spec
+postgrest-check                   postgrest-watch
+postgrest-clean                   postgrest-with-all
+postgrest-coverage                postgrest-with-postgresql-10
+postgrest-lint                    postgrest-with-postgresql-11
+postgrest-run                     postgrest-with-postgresql-12
+postgrest-style                   postgrest-with-postgresql-13
+postgrest-style-check             postgrest-with-postgresql-9.5
+postgrest-test-io                 postgrest-with-postgresql-9.6
+postgrest-test-memory
+...
+
+```
+
+Note that `postgrest-test-memory` is now also available.
+
+To run one-off commands, you can also use `nix-shell --run <command>`, which
+will lauch the Nix shell, run that one command and exit. Note that the tab
+completion will not work with `nix-shell --run`, as Nix has yet to evaluate
+our Nix expressions to see which utilities are available.
+
+```bash
+$ nix-shell --run postgrest-style
+
+# Note that you need to quote any arguments that you would like to pass to
+# the command to be run in nix-shell:
+$ nix-shell --run "postgrest-foo --bar"
+
+```
+
+A third option is to install utilities that you use very often locally:
+
+```bash
+$ nix-env -f default.nix -iA devTools
+
+# `postgrest-style` can now be run directly:
+$ postgrest-style
+
+```
+
+If you use `nix-shell` very often, you might like to use
+https://github.com/xzfc/cached-nix-shell, which skips evaluating all our Nix
+expressions if nothing changed, reducing startup time for the shell
+considerably.
+
+Note: Once inside nix-shell, the utilities work from any directory inside
+the PostgREST repo. Paths are resolved relative to the repo root:
+
+```bash
+$ cd src
+# Even though the current directory is ./src, the config path must still start
+# from the repo root:
+$ postgrest-run test/io-tests/configs/simple.conf
+```
+
+## Testing
+
+In nix-shell, you'll find utility scripts that make it very easy to run the
+Haskell test suite, including setting up all required dependencies and
+temporary test databases:
+
+```bash
+# Run the tests against the most recent version of PostgreSQL:
+$ nix-shell --run postgrest-test-spec
+
+# Run the tests against all supported versions of PostgreSQL:
+$ nix-shell --run "postgrest-with-all postgrest-test-spec"
+
+# Run the tests against a specific version of PostgreSQL (use tab-completion in
+# nix-shell to see all available versions):
+$ nix-shell --run "postgrest-with-postgresql-13 postgrest-test-spec"
+
+```
+
+The io-test that test PostgREST as a black box with inputs and outputs can be
+run with `postgrest-test-io`. The test runner under the hood is
+[pytest](https://docs.pytest.org/) and you can pass it the usual options:
+
+```bash
+# Filter the tests to run by name, including all that contain 'config':
+postgrest-test-io -k config
+
+# Run tests in parallel using xdist, specifying the number of processes:
+postgrest-test-io -n auto
+postgrest-test-io -n 8
+
+```
+
+## Linting and styling code
+
+The nix-shell also contains scripts for linting and styling the PostgREST
+source code:
+
+```bash
+# Linting
+$ nix-shell --run postgrest-lint
+
+# Styling / auto-formatting code
+$ nix-shell --run postgrest-style
+
+```
+
+There is also `postgrest-style-check` that exits with a non-zero exit code if
+the check resulted in any uncommited changes. It's mostly useful for CI.
+
+## General development tools
+
+Tools like `postgrest-build`, `postgrest-run` etc. are simple wrappers around
+`cabal` and should do what you expect. `postgrest-check` runs most checks that will
+also run in CI, with the exception of the IO and Memory checks that need to be run
+separately.
+
+`postgrest-with-postgresql-*` take a command as an argument and will run it
+with a temporary database. `postgrest-with-all` will run the command against
+all supported PostgreSQL versions. Tests run without `postgrest-with-*` are
+run against the latest PostgreSQL version by default.
+
+`postgrest-watch` takes a command as an argument that it will re-run if any source
+file is changed. For example, `postgrest-watch postgrest-with-all postgrest-test-spec`
+will re-run the full spec test suite against all PostgreSQL versions on every change.
+
+## Tour
+
+The following is not required for working on PostgREST with Nix, but it will
+give you some more background and details on how it works.
+
+### `default.nix`
+
+[`default.nix`](../default.nix) is our 'repository expression' that pulls all
+the pieces that we define with Nix together. It returns a set (like a dict in
+other programming languages), where each attribute is a derivation that Nix
+knows how to build, like the `postgrest` attribute from earlier.
+
+Internally, our `default.nix` uses the `pkgs.callPackage` function to import
+the modules that we defined in the `nix` directory. It automatically passes the
+arguments those modules require if they are available in `pkgs` (this means
+that `pkgs` is defined in terms of itself, better not to think too much about
+that).
+
+We also use `default.nix` to load our pinned version of the `nixpkgs`
+repository. This set of packages will always be the same, independently from
+where or when you use it. The pinned version can be upgraded with the small
+`nixpkgs-upgrade` utility. Running `nixpkgs-upgrade > nix/nixpkgs-version.nix`
+in `nix-shell` will upgrade the pinned version to the latest `nixpkgs-unstable`
+version.
+
+### `shell.nix`
+
+[`shell.nix`](../shell.nix) defines an environment in which PostgREST can be
+built and developed. It extends the build enviroment from our `postgrest`
+attribute with useful utilities that will be put on the PATH in `nix-shell`.
+
+### `nix/overlays`
+
+Our overlays to the Nix package set are defined here. They allow us to tweak our
+`pkgs` in `default.nix` by adding new packages or overriding existing ones.
+
+## Upgrading dependencies
+
+See the [upgrading checklist](UPGRADE.md) for how to upgrade the PostgREST
+dependencies.

nix/UPGRADE.md

@@ -0,0 +1,91 @@
+# Checklist for upgrading Nix dependencies
+
+The Nix dependencies of PostgREST should be updated regularly, in most cases it
+should be a very simple operation.
+
+```bash
+# Update pinned version of Nixpkgs
+nix-shell --run postgrest-nixpkgs-upgrade
+
+# Verify that everything builds
+nix-build
+```
+
+The following checklist guides you through the complete process in more detail.
+
+## Upgrade the pinned version of `nixpkgs`
+
+The pinned version of [`nixpkgs`](https://github.com/NixOS/nixpkgs) is defined
+in [`nix/nixpkgs-version.nix`](nixpkgs-version.nix). The pin refers directly to
+a GitHub tarball for the given revision, which is more efficient than pulling
+the complete Git repository. To upgrade it to the current `main` of
+`nixpkgs`, you can use a small utility script defined in
+[`nix/nixpkgs-update.nix`](nixpkgs-update.nix):
+
+```bash
+# From the root of the repository, enter nix-shell
+nix-shell
+
+# Run the utility script to pin the latest revision in main
+postgrest-nixpkgs-upgrade
+
+# Exit the nix-shell with Ctrl-d
+
+```
+
+## Update pinned version of `static-haskell-nix`
+
+We pin [`static-haskell-nix`](https://github.com/nh2/static-haskell-nix) in
+[`nix/static-haskell-package.nix`](static-haskell-package.nix). Upgrade the
+pinned revision and the tarball hash if necessary. See
+[`nix/nixpkgs-upgrade.nix`](nixpkgs-upgrade.nix) for how to get the correct
+tarball hash, or just change the hash to an arbitrary value of correct length,
+run `nix-build` and use the expected value from the resulting error message.
+
+## Review overlays
+
+Check whether the individual [overlays](overlays) are still required.
+
+## Check if patches are still required and update them as needed
+
+We track a number of PostgREST-specific patches in [`nix/patches`](patches).
+Check whether the pull-requests/issues linked in the
+[`default.nix`](patches/default.nix) have progressed and remove/modify the
+patches if they did. If conflicting changes occurred, you might have to rebase
+the respective patches.
+
+## Build everything
+
+Using the PostgREST binary Nix cache is recommended. Install
+[Cachix](https://cachix.org/) and run `cachix use postgrest`.
+
+Run `nix-build` in the root directory of the project to build all PostgREST
+artifacts. This might take a long time, e.g. when our static GHC version needs
+to be rebuilt due to changes to some underlying package. If there are any
+errors, this is probably due to one of our patches. Try to fix them and re-run
+`nix-build` until everything builds.
+
+## Update the PostgREST binary cache
+
+If you have access to the PostgREST cachix signing key, you can push the
+artifacts that you built locally to the binary cache. This will accelerate the
+CI builds and tests, sometimes dramatically. This might sometimes even be
+required to avoid build timeouts in CI.
+
+You'll need to set the `CACHIX_SIGNING_KEY` before proceeding, e.g. by creating
+a file containing `export CACHIX_SIGNING_KEY=...` and sourcing that file, which
+avoids having the secret in you shell history.
+
+To push all new artifacts to Cachix, run:
+
+```
+nix-store -qR --include-outputs $$(nix-instantiate) | cachix push postgrest
+
+# Or, equivalently
+nix-shell --run postgrest-push-cachix
+
+```
+
+The `nix-store` command will query the nix-store to list all dependencies and
+build artifacts of PostgREST. The `cachix` command will efficiently push
+everything that is not yet cached to the binary cache.

nix/docker-compose.yml

@@ -0,0 +1,12 @@
+version: '3'
+
+services:
+  nix:
+    container_name: postgrest-nix
+    build: .
+    volumes:
+      - ../:/postgrest
+      - nix:/nix
+
+volumes:
+  nix:

nix/hsie/Main.hs

@@ -0,0 +1,358 @@
+{-# LANGUAGE DeriveAnyClass    #-}
+{-# LANGUAGE DeriveGeneric     #-}
+{-# LANGUAGE NamedFieldPuns    #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards   #-}
+{-# LANGUAGE TupleSections     #-}
+{-# LANGUAGE TypeFamilies      #-}
+
+-- | Haskell Imports and Exports tool
+--
+-- This tool parses imports and exports from Haskell source files and provides
+-- analysis on these imports. For example, you can check whether consistent
+-- import aliases are used across your codebase.
+
+module Main (main) where
+
+import qualified Data.Aeson                              as JSON
+import qualified Data.ByteString.Lazy.Char8              as LBS8
+import qualified Data.Csv                                as Csv
+import qualified Data.Map                                as Map
+import qualified Data.Set                                as Set
+import qualified Data.Text                               as T
+import qualified Data.Text.IO                            as T
+import qualified Dot
+import qualified GHC
+import qualified Language.Haskell.GHC.ExactPrint.Parsers as ExactPrint
+import qualified Options.Applicative                     as O
+import qualified System.FilePath                         as FP
+
+import Data.Aeson.Encode.Pretty   (encodePretty)
+import Data.Function              ((&))
+import Data.List                  (intercalate)
+import Data.Maybe                 (catMaybes, mapMaybe)
+import Data.Text                  (Text)
+import GHC.Generics               (Generic)
+import HsExtension                (GhcPs)
+import Module                     (moduleNameString)
+import OccName                    (occNameString)
+import RdrName                    (rdrNameOcc)
+import System.Directory.Recursive (getFilesRecursive)
+import System.Exit                (exitFailure)
+
+-- TYPES
+
+data Options =
+  Options
+    { command :: Command
+    , sources :: [FilePath]
+    }
+
+data Command
+  = Dump OutputFormat
+  | GraphSymbols
+  | GraphModules
+  | CheckAliases
+  | CheckWildcards [Text]
+
+data OutputFormat = OutputCsv | OutputJson
+
+data ImportedSymbol =
+  ImportedSymbol
+    { impFromModule :: Text
+    , impModule     :: Text
+    , impQualified  :: ImportQualified
+    , impAlias      :: Maybe Text
+    , impType       :: ImportType
+    , impSymbol     :: Maybe Text
+    , impInternal   :: ModuleInternal
+    , impSource     :: FilePath
+    , impFile       :: FilePath
+    }
+    deriving (Generic, Csv.ToNamedRecord, Csv.DefaultOrdered, JSON.ToJSON)
+
+data ImportQualified
+  = Qualified
+  | NotQualified
+  deriving (Eq, Generic, JSON.ToJSON)
+
+instance Csv.ToField ImportQualified where
+  toField Qualified    = "qualified"
+  toField NotQualified = "not qualified"
+
+data ModuleInternal
+  = Internal
+  | External
+  deriving (Eq, Generic, JSON.ToJSON)
+
+instance Csv.ToField ModuleInternal where
+  toField Internal = "internal"
+  toField External = "external"
+
+data ImportType
+  = Wildcard
+  | Hiding
+  | Explicit
+  deriving (Eq, Generic, JSON.ToJSON)
+
+instance Csv.ToField ImportType where
+  toField Wildcard = "wildcard"
+  toField Hiding   = "hiding"
+  toField Explicit = "explicit"
+
+-- | Mapping of modules to their aliases and to the files they are found in
+type ModuleAliases = [(Text, [(Text, [FilePath])])]
+
+-- | Mapping of modules to files
+type WildcardImports = [(FilePath, [Text])]
+
+
+-- MAIN
+
+main :: IO ()
+main =
+  run =<< O.customExecParser prefs infoOpts
+  where
+    prefs = O.prefs $ O.subparserInline <> O.showHelpOnEmpty
+    infoOpts =
+      O.info (O.helper <*> opts) $
+        O.fullDesc
+        <> O.header "hsie - Swiss army knife for HaSkell Imports and Exports"
+        <> O.progDesc "Parse Haskell code to analyze imports and exports"
+    opts =
+      Options <$> commandOption <*> O.some srcOption
+    srcOption =
+      O.argument O.str $
+        O.metavar "SRCDIR"
+        <> O.help "Haskell source directory"
+        <> O.action "directory"
+    commandOption =
+      O.subparser $
+        command "dump-imports" "Dump imported symbols as CSV or JSON"
+          (Dump <$> jsonOutputFlag)
+        <> command "graph-modules" "Print dot graph of module imports"
+             (pure GraphModules)
+        <> command "graph-symbols" "Print dot graph of symbol imports"
+             (pure GraphSymbols)
+        <> command "check-aliases"
+             "Check that aliases of imported modules are consistent"
+             (pure CheckAliases)
+        <> command "check-wildcards"
+             "Check that no modules are imported as unqualified wildcards"
+             (CheckWildcards <$> O.many okModuleOption)
+    command name desc options =
+      O.command name . O.info (O.helper <*> options) $ O.progDesc desc
+    jsonOutputFlag =
+      O.flag OutputCsv OutputJson $
+        O.long "json" <> O.short 'j' <> O.help "Output JSON"
+    okModuleOption =
+      O.strOption $
+        O.long "ok"
+        <> O.short 'o'
+        <> O.metavar "OKMODULE"
+        <> O.help "Module that is ok to import as unqualified wildcard"
+
+run :: Options -> IO ()
+run Options{command, sources} =
+  runCommand command . markInternal . concat =<< mapM sourceSymbols sources
+  where
+    runCommand :: Command -> [ImportedSymbol] -> IO ()
+    runCommand (Dump format) = LBS8.putStr . dump format
+    runCommand GraphSymbols = T.putStr . symbolsGraph
+    runCommand GraphModules = T.putStr . Dot.encode . modulesGraph
+    runCommand CheckAliases = runInconsistentAliases . inconsistentAliases
+    runCommand (CheckWildcards okModules) = runWildcards . wildcards okModules
+
+    runInconsistentAliases :: ModuleAliases -> IO ()
+    runInconsistentAliases [] = T.putStrLn "No inconsistent module aliases found."
+    runInconsistentAliases xs = T.putStr (formatInconsistentAliases xs) >> exitFailure
+
+    runWildcards :: WildcardImports -> IO ()
+    runWildcards [] = T.putStrLn "No unwanted wildcard imports found."
+    runWildcards xs = T.putStr (formatWildcards xs) >> exitFailure
+
+-- | Mark imports from modules that are among the analyzed ones as internal.
+markInternal :: [ImportedSymbol] -> [ImportedSymbol]
+markInternal symbols =
+  fmap mark symbols
+  where
+    mark s = s { impInternal = if isInternal s then Internal else External }
+    isInternal = flip Set.member internalModules . impModule
+    internalModules = Set.fromList $ fmap impFromModule symbols
+
+
+-- SYMBOLS
+
+-- | Parse all imported symbols from a source of Haskell source files
+sourceSymbols :: FilePath -> IO [ImportedSymbol]
+sourceSymbols source = do
+  files <- filterExts [".hs", ".imports"] <$> getFilesRecursive source
+  concat <$> mapM moduleSymbols files
+  where
+    filterExts exts = filter $ flip elem exts . FP.takeExtension
+    moduleSymbols filepath = do
+      GHC.HsModule{..} <- parseModule filepath
+      return $ concatMap (importSymbols source filepath . GHC.unLoc) hsmodImports
+
+-- | Parse a Haskell module
+parseModule :: String -> IO (GHC.HsModule GhcPs)
+parseModule filepath = do
+  result <- ExactPrint.parseModule filepath
+  case result of
+    Right (_, hsmod) ->
+      return $ GHC.unLoc hsmod
+    Left (loc, err) ->
+      fail $ "Error with " <> show filepath <> " at " <> show loc <> ": " <> err
+
+-- | Symbols imported in an import declaration.
+--
+-- If the import is a wildcard, i.e. no symbols are selected for import, then
+-- only one item is returned.
+importSymbols :: FilePath -> FilePath -> GHC.ImportDecl GhcPs -> [ImportedSymbol]
+importSymbols _ _  (GHC.XImportDecl _) = mempty
+importSymbols source filepath GHC.ImportDecl{..} =
+  case ideclHiding of
+    Just (hiding, syms) ->
+      symbol (if hiding then Hiding else Explicit) . Just . GHC.unLoc <$> GHC.unLoc syms
+    Nothing ->
+      [ symbol Wildcard Nothing ]
+  where
+    symbol hiding sym =
+      ImportedSymbol
+        { impFile = relativePath filepath
+        , impSource = source
+        , impFromModule = T.pack $ moduleFromPath filepath
+        , impModule = T.pack . moduleNameString . GHC.unLoc $ ideclName
+        , impQualified = if ideclQualified then Qualified else NotQualified
+        , impAlias = T.pack . moduleNameString . GHC.unLoc <$> ideclAs
+        , impInternal = External
+        , impType = hiding
+        , impSymbol = T.pack . occNameString . rdrNameOcc . GHC.ieName <$> sym
+        }
+    moduleFromPath =
+      intercalate "." . FP.splitDirectories . FP.dropExtension . relativePath
+    relativePath = FP.makeRelative source
+
+
+-- DUMP
+
+-- | Dump list of symbols as CSV or JSON
+dump :: OutputFormat -> [ImportedSymbol] -> LBS8.ByteString
+dump OutputCsv  = Csv.encodeDefaultOrderedByName
+dump OutputJson = encodePretty
+
+
+-- ALIASES
+
+-- | Find modules that are imported under different aliases
+inconsistentAliases :: [ImportedSymbol] -> ModuleAliases
+inconsistentAliases symbols =
+  fmap moduleAlias symbols
+    & foldr insertSetMapMap Map.empty
+    & Map.map (aliases . Map.toList)
+    & Map.filter ((<) 1 . length)
+    & Map.toList
+  where
+    moduleAlias ImportedSymbol{..} =
+      (impModule, impAlias, FP.joinPath [impSource, impFile])
+    insertSetMapMap (k1, k2, v) =
+      Map.insertWith (Map.unionWith Set.union) k1
+        (Map.singleton k2 $ Set.singleton v)
+    aliases :: [(Maybe Text, Set.Set FilePath)] -> [(Text, [FilePath])]
+    aliases = mapMaybe (\(k, v) -> fmap (, Set.toList v) k)
+
+formatInconsistentAliases :: ModuleAliases -> Text
+formatInconsistentAliases modules =
+  "The following imports have inconsistent aliases:\n\n"
+    <> T.concat (fmap formatModule modules)
+  where
+    formatModule (modName, aliases) =
+      "Module '"
+        <> modName
+        <> "' has the aliases:\n"
+        <> T.concat (fmap formatAlias aliases)
+        <> "\n"
+    formatAlias (alias, sourceFiles) =
+      "  '"
+        <> alias
+        <> "' in file"
+        <> (if length sourceFiles > 2 then "s" else "")
+        <> ":\n"
+        <> T.concat (fmap formatFile sourceFiles)
+    formatFile sourceFile =
+      "    " <> T.pack sourceFile <> "\n"
+
+
+-- WILDCARDS
+
+-- | Find modules that are imported as wildcards, excluding whitelisted modules.
+--
+-- Wildcard imports are ones that are not qualified and do not specify which
+-- symbols should be imported.
+wildcards :: [Text] -> [ImportedSymbol] -> WildcardImports
+wildcards okModules =
+  groupByFile . filter isWildcard . filter (not . isOkModule)
+  where
+    isWildcard ImportedSymbol{..} =
+      impQualified == NotQualified && impType /= Explicit
+    isOkModule = flip Set.member (Set.fromList okModules) . impModule
+    groupByFile = Map.toList . fmap Set.toList . foldr insertMap Map.empty
+    insertMap ImportedSymbol{..} =
+      Map.insertWith Set.union impFile (Set.singleton impModule)
+
+formatWildcards :: WildcardImports -> Text
+formatWildcards files =
+  "Modules in the following files were imported as wildcards:\n\n"
+    <> T.concat (fmap formatFile files)
+  where
+    formatFile (filepath, modules) =
+      "In " <> T.pack filepath <> ":\n" <> T.concat (fmap formatModule modules) <> "\n"
+    formatModule moduleName = "  " <> moduleName <> "\n"
+
+
+-- GRAPHS
+
+modulesGraph :: [ImportedSymbol] -> Dot.DotGraph
+modulesGraph symbols =
+  Dot.DotGraph Dot.Strict Dot.Directed (Just "Modules") $ fmap edge edges
+  where
+    edge (from, to) =
+      Dot.StatementEdge $ Dot.EdgeStatement
+        (Dot.ListTwo (edgeNode from) (edgeNode to) mempty) mempty
+    edgeNode t = Dot.EdgeNode $ Dot.NodeId (Dot.Id t) Nothing
+    edges = unique . fmap edgeTuple . filter ((==) Internal . impInternal) $ symbols
+    edgeTuple ImportedSymbol{..} = (impFromModule, impModule)
+    unique = Set.toList . Set.fromList
+
+-- Building Text directly as the Dot package currently doesn't support subgraphs.
+symbolsGraph :: [ImportedSymbol] -> Text
+symbolsGraph symbols =
+  "digraph Symbols {\n"
+    <> "  rankdir=LR\n"
+    <> "  ranksep=5\n"
+    <> T.concat (fmap edge edges)
+    <> T.concat (fmap cluster symbolsByModule)
+    <> "}\n"
+  where
+    edge (from, to, symbol) =
+      "  "
+        <> quoted from
+        <> " -> "
+        <> quoted (to <> maybe "" ("." <>) symbol)
+        <> "\n"
+    cluster (moduleName, clusterSymbols) =
+      "  subgraph "
+        <> quoted ("cluster_" <> moduleName)
+        <> " {\n"
+        <> "    " <> quoted moduleName <> "\n"
+        <> T.concat (fmap (clusterNode moduleName) clusterSymbols)
+        <> "  }\n"
+    clusterNode moduleName symbol =
+      "    " <> quoted (moduleName <> "." <> symbol) <> "\n"
+    quoted t = "\"" <> t <> "\""
+    edges = unique . fmap edgeTuple . filter ((==) Internal . impInternal) $ symbols
+    edgeTuple ImportedSymbol{..} = (impFromModule, impModule, impSymbol)
+    unique = Set.toList . Set.fromList
+    symbolsByModule =
+      Map.toList . Map.map (catMaybes . Set.toList) . foldr insertMap Map.empty $ edges
+    insertMap (_, to, symbol) = Map.insertWith Set.union to $ Set.singleton symbol

nix/hsie/README.md

@@ -0,0 +1,67 @@
+# hsie - Swiss army knife for HaSkell Imports and Exports
+
+This tool parses Haskell source code to analyse the imports and exports in a
+project. It's available in PostgREST's `nix-shell` by default.
+
+## Dumping imports
+
+Given source code in the directories `src` and `main`, for example, you can run:
+
+```
+hsie dump-imports src main
+```
+
+This dumps all imports of the modules in the given directory to a CSV file,
+printed on `stdout`.
+
+To dump to a JSON file (e.g., to further process with `jq`), add the `--json`
+flag:
+
+```
+hsie dump-imports --json src main
+```
+
+## Graphing imports
+
+The tool can generate `graphviz` graphs of module and symbol imports by printing
+a file to `stdout` that can directly be rendered with `dot`:
+
+```
+hsie graph-modules src main | dot -Tpng -o modules.png
+```
+
+The command `graph-modules` prints a graph of which modules insert which other
+modules. `graph-symbols` shows which symbols are imported from which modules.
+
+## Checking imports
+
+To check whether modules are imported under consistent aliases in your project,
+run:
+
+```
+hsie check-aliases main src
+```
+
+This will exit with a non-zero exit code if any inconsistent aliases are found.
+
+The following command checks whether any modules are imported as wildcards, i.e.
+not qualified and without specifying symbols.
+
+```
+hsie check-wildcards main src
+```
+
+To whitelist certain modules to be imported as wildcards, use `--ok`:
+
+```
+hsie check-wildcards main src --ok Protolude --ok Test.Module
+```
+
+## Current limitations
+
+This tool uses the GHC parser to parse Haskell source code. Language extensions
+required to parse each file are detected based on the `{-# LANGUAGE ... #-}`
+pragmas. If they are not available (e.g., as they are listed as default
+extensions in the `.cabal` file), parses may fail. We can fix this by using
+an extended set of non-conflicting extensions by default, as `hlint` does for
+example.

nix/hsie/default.nix

@@ -0,0 +1,30 @@
+{ ghcWithPackages
+, runCommand
+}:
+let
+  name = "hsie";
+  src = ./Main.hs;
+  modules = ps: [
+    ps.aeson
+    ps.aeson-pretty
+    ps.cassava
+    ps.dir-traverse
+    ps.dot
+    ps.ghc-exactprint
+    ps.optparse-applicative
+  ];
+  ghc = ghcWithPackages modules;
+  hsie =
+    runCommand "haskellimports" { inherit name src; }
+      "${ghc}/bin/ghc -O -Werror -Wall -package ghc $src -o $out";
+  bin =
+    runCommand name { inherit hsie name; }
+      ''
+        mkdir -p $out/bin
+        ln -s $hsie $out/bin/$name
+      '';
+  bashCompletion =
+    runCommand "${name}-bash-completion" { inherit bin name; }
+      "$bin/bin/$name --bash-completion-script $bin/bin/$name > $out";
+in
+hsie // { inherit bashCompletion bin; }

nix/nixpkgs-version.nix

@@ -0,0 +1,6 @@
+# Pinned version of Nixpkgs, generated with postgrest-nixpkgs-upgrade.
+{
+  date = "2021-07-17";
+  rev = "d00b5a5fa6fe8bdf7005abb06c46ae0245aec8b5";
+  tarballHash = "08497wbpnf3w5dalcasqzymw3fmcn8qrnbkf8rxxwwvyjdnczxdv";
+}

nix/overlays/build-toolbox/build-toolbox.nix

@@ -0,0 +1,16 @@
+# Creates an environment that exposes bashCompletion arguments from all checkedShellScripts
+{ buildEnv }:
+{ name
+, tools
+, extra ? { }
+}:
+let
+  bashCompletion = builtins.map (tool: tool.bashCompletion) tools;
+
+  env = buildEnv {
+    inherit name;
+    paths = builtins.map (tool: tool.bin) tools;
+  };
+
+in
+env // { inherit bashCompletion; } // extra

nix/overlays/build-toolbox/default.nix

@@ -0,0 +1,5 @@
+self: super:
+# Overlay that adds `buildToolbox`, an enhanced version of `buildEnv`
+{
+  buildToolbox = super.callPackage ./build-toolbox.nix { };
+}

nix/overlays/checked-shell-script/checked-shell-script.nix

@@ -0,0 +1,137 @@
+# Create a bash script that is checked with shellcheck. You can either use it
+# directly, or use the .bin attribute to get the script in a bin/ directory,
+# to be used in a path for example.
+{ argbash
+, bash_5
+, coreutils
+, git
+, lib
+, runCommand
+, shellcheck
+, stdenv
+, writeTextFile
+}:
+{ name
+, docs
+, args ? [ ]
+, addCommandCompletion ? false
+, inRootDir ? false
+, redirectTixFiles ? true
+, withEnv ? null
+, withTmpDir ? false
+}: text:
+let
+  argsTemplate =
+    let
+      # square brackets are a pain to escape - if even possible. just don't use them...
+      escapedDocs = builtins.replaceStrings [ "\n" ] [ " \\n" ] docs;
+    in
+    writeTextFile {
+      inherit name;
+      destination = "/${name}.m4"; # destination is needed to have the proper basename for completion
+
+      text =
+        ''
+          # BASH_ARGV0 sets $0 - which is used in parser.sh for usage information
+          # stripping the /nix/store/... path for nicer display
+          BASH_ARGV0="$(basename "$0")"
+
+          # ARG_HELP([${name}], [${escapedDocs}])
+          ${lib.strings.concatMapStrings (arg: "# " + arg) args}
+          # ARG_POSITIONAL_DOUBLEDASH()
+          # ARG_DEFAULTS_POS()
+          # ARGBASH_GO
+
+        '';
+    };
+
+  argsParser =
+    runCommand "${name}-parser" { }
+      ''
+        ${argbash}/bin/argbash ${argsTemplate}/${name}.m4 > $out
+
+        # This forces optional arguments to go *before* positional arguments,
+        # which allows leftovers to pass optional arguments to sub-commands.
+        # Example: This way `postgrest-watch -h` will return the help output for watch, while
+        # `postgrest-watch postgrest-test-spec -h` will return the help output for test-spec.
+        # Taken from: https://github.com/matejak/argbash/issues/114#issuecomment-557108274
+        sed '/_positionals_count + 1/a\\t\t\t\tset -- "''${@:1:1}" "--" "''${@:2}"' -i $out
+      '';
+
+  bashCompletion =
+    runCommand "${name}-completion" { } (
+      ''
+        ${argbash}/bin/argbash --type completion --strip all ${argsTemplate}/${name}.m4 > $out
+      ''
+
+      + lib.optionalString addCommandCompletion ''
+        sed 's/COMPREPLY.*compgen -o bashdefault .*$/_command/' -i $out
+      ''
+    );
+
+  bin =
+    writeTextFile {
+      inherit name;
+      executable = true;
+      destination = "/bin/${name}";
+
+      text =
+        ''
+          #!${bash_5}/bin/bash
+          source ${argsParser}
+          set -euo pipefail
+        ''
+
+        + lib.optionalString redirectTixFiles ''
+          # storing tix files in a temporary throw away directory avoids mix/tix conflicts after changes
+          hpctixdir=$(${coreutils}/bin/mktemp -d)
+          export HPCTIXFILE="$hpctixdir"/postgrest.tix
+          trap 'rm -rf $hpctixdir' EXIT
+        ''
+
+        + lib.optionalString inRootDir ''
+          cd "$(${git}/bin/git rev-parse --show-toplevel)"
+
+          if test ! -f postgrest.cabal; then
+            >&2 echo "Couldn't find postgrest.cabal. Please make sure to" \
+                     "run this command somewhere in the PostgREST repo."
+            exit 1
+          fi
+        ''
+
+        + lib.optionalString withTmpDir ''
+          mkdir -p "''${TMPDIR:-/tmp}/postgrest"
+          tmpdir="$(${coreutils}/bin/mktemp -d --tmpdir postgrest/${name}-XXX)"
+
+          # we keep the tmpdir when an error occurs for debugging
+          trap 'echo Temporary directory kept at: $tmpdir' ERR
+          # remove the tmpdir when cancelled (postgrest-watch)
+          trap 'rm -rf "$tmpdir"' SIGINT SIGTERM
+        ''
+
+        + lib.optionalString (withEnv != null) ''
+          env="$(cat ${withEnv})"
+          export PATH="$env/bin:$PATH"
+        ''
+
+        + "(${text})"
+
+        + lib.optionalString withTmpDir ''
+
+          rm -rf "$tmpdir"
+        '';
+
+      checkPhase =
+        ''
+          # check syntax
+          ${stdenv.shell} -n $out/bin/${name}
+
+          # check for shellcheck recommendations
+          ${shellcheck}/bin/shellcheck -x $out/bin/${name}
+        '';
+    };
+
+  script =
+    runCommand name { inherit bin name; } "ln -s $bin/bin/$name $out";
+in
+script // { inherit bin bashCompletion; }

nix/overlays/checked-shell-script/default.nix

@@ -0,0 +1,6 @@
+self: super:
+# Overlay that adds `checkedShellScript`, an enhanced version of
+# writeShellScript and writeShellScriptBin
+{
+  checkedShellScript = super.callPackage ./checked-shell-script.nix { };
+}

nix/overlays/default.nix

@@ -0,0 +1,9 @@
+{
+  build-toolbox = import ./build-toolbox;
+  checked-shell-script = import ./checked-shell-script;
+  ghr = import ./ghr;
+  gitignore = import ./gitignore.nix;
+  haskell-packages = import ./haskell-packages.nix;
+  postgresql-default = import ./postgresql-default.nix;
+  postgresql-legacy = import ./postgresql-legacy.nix;
+}

nix/overlays/ghr/default.nix

@@ -0,0 +1,7 @@
+self: super:
+# Overlay that adds `ghr`: Upload multiple artifacts to GitHub Release in
+# parallel, http://tcnksm.github.io/ghr/
+
+{
+  ghr = super.callPackage ./ghr.nix { };
+}

nix/overlays/ghr/ghr.nix

@@ -0,0 +1,18 @@
+{ buildGoModule, fetchFromGitHub }:
+
+buildGoModule rec {
+  pname = "ghr";
+  version = "0.14.0";
+
+  src = fetchFromGitHub {
+    rev = "v${version}";
+    owner = "tcnksm";
+    repo = "ghr";
+    sha256 = "1jjc3bwmyw831r1ayic1f1ysh5ggm88aszbndm0swg8byhz56pd4";
+  };
+
+  vendorSha256 = "06cbhsnxv4gisnwrhw61af7rpv2a9slf9z2wbn79r91xzkh51vzr";
+
+  # Disabling tests, as they require a GitHub API token
+  doCheck = false;
+}

nix/overlays/gitignore.nix

@@ -0,0 +1,20 @@
+self: super:
+# Overlay that adds the `gitignoreSource` function from Hercules-CI.
+# This function is useful for filtering which files are added to the Nix store.
+# See: https://github.com/hercules-ci/gitignore.nix
+
+# To update to a newer revision, the simplest way is to add a new commit hash
+# from GitHub under `rev` and to then add the hash that Nix suggests on first
+# use.
+{
+  gitignoreSource =
+    let
+      gitignoreSrc = super.fetchFromGitHub {
+        owner = "hercules-ci";
+        repo = "gitignore";
+        rev = "211907489e9f198594c0eb0ca9256a1949c9d412";
+        sha256 = "06j7wpvj54khw0z10fjyi31kpafkr6hi1k0di13k1xp8kywvfyx8";
+      };
+    in
+    (super.callPackage gitignoreSrc { }).gitignoreSource;
+}

nix/overlays/haskell-packages.nix

@@ -0,0 +1,42 @@
+{ compiler, extraOverrides ? (final: prev: { }) }:
+
+self: super:
+let
+  lib =
+    self.haskell.lib;
+
+  overrides =
+    final: prev:
+    rec {
+      # To pin custom versions of Haskell packages:
+      #   protolude =
+      #     prev.callHackageDirect
+      #       {
+      #         pkg = "protolude";
+      #         ver = "0.3.0";
+      #         sha256 = "0iwh4wsjhb7pms88lw1afhdal9f86nrrkkvv65f9wxbd1b159n72";
+      #       }
+      #       { };
+      #
+      # To get the sha256:
+      #   nix-prefetch-url --unpack https://hackage.haskell.org/package/protolude-0.3.0/protolude-0.3.0.tar.gz
+
+      hasql-dynamic-statements =
+        lib.dontCheck (lib.unmarkBroken prev.hasql-dynamic-statements);
+
+      hasql-implicits =
+        lib.dontCheck (lib.unmarkBroken prev.hasql-implicits);
+
+      ptr =
+        lib.dontCheck (lib.unmarkBroken prev.ptr);
+    } // extraOverrides final prev;
+in
+{
+  haskell =
+    super.haskell // {
+      packages = super.haskell.packages // {
+        "${compiler}" =
+          super.haskell.packages."${compiler}".override { inherit overrides; };
+      };
+    };
+}

nix/overlays/postgresql-default.nix

@@ -0,0 +1,5 @@
+self: super:
+# Overlay that sets the default version of PostgreSQL.
+{
+  postgresql = super.postgresql_13;
+}

nix/overlays/postgresql-legacy.nix

@@ -0,0 +1,20 @@
+self: super:
+# Overlay that adds legacy versions of PostgreSQL that are supported by
+# PostgREST.
+{
+  # PostgreSQL 9.5 was removed from Nixpkgs with
+  # https://github.com/NixOS/nixpkgs/commit/72ab382fb6b729b0d654f2c03f5eb25b39f11fbb
+  # We pin its parent commit to get the last version that was available.
+  postgresql_9_5 =
+    let
+      rev = "55ac7d4580c9ab67848c98cb9519317a1cc399c8";
+      tarballHash = "02ffj9f8s1hwhmxj85nx04sv64qb6jm7w0122a1dz9n32fymgklj";
+
+      pinnedPkgs =
+        builtins.fetchTarball {
+          url = "https://github.com/nixos/nixpkgs/archive/${rev}.tar.gz";
+          sha256 = tarballHash;
+        };
+    in
+    (import pinnedPkgs { }).pkgs.postgresql_9_5;
+}

nix/patches/default.nix

@@ -0,0 +1,24 @@
+{ runCommand }:
+
+{
+  applyPatches =
+    name: src: patches:
+    runCommand
+      name
+      { inherit src patches; }
+      ''
+        set -eou pipefail
+
+        cp -r $src $out
+        chmod -R u+w $out
+
+        for patch in $patches; do
+          echo "Applying patch $patch"
+          patch -d "$out" -p1 < "$patch"
+        done
+      '';
+
+  # See: https://github.com/NixOS/nixpkgs/pull/87879
+  nixpkgs-openssl-split-runtime-dependencies-of-static-builds =
+    ./nixpkgs-openssl-split-runtime-dependencies-of-static-builds.patch;
+}

nix/patches/nixpkgs-openssl-split-runtime-dependencies-of-static-builds.patch

@@ -0,0 +1,76 @@
+diff --git a/pkgs/development/libraries/openssl/default.nix b/pkgs/development/libraries/openssl/default.nix
+index d4be8cc2428..3979698711f 100644
+--- a/pkgs/development/libraries/openssl/default.nix
++++ b/pkgs/development/libraries/openssl/default.nix
+@@ -50,9 +50,21 @@ let
+       substituteInPlace crypto/async/arch/async_posix.h \
+         --replace '!defined(__ANDROID__) && !defined(__OpenBSD__)' \
+                   '!defined(__ANDROID__) && !defined(__OpenBSD__) && 0'
++    '' + optionalString static
++    # On static builds, the ENGINESDIR will be empty, but its path will be
++    # compiled into the library. In order to minimize the runtime dependencies
++    # of packages that statically link openssl, we move it into the OPENSSLDIR,
++    # which will be separated into the 'etc' output.
++    ''
++      substituteInPlace Configurations/unix-Makefile.tmpl \
++        --replace 'ENGINESDIR=$(libdir)/engines-{- $sover_dirname -}' \
++                  'ENGINESDIR=$(OPENSSLDIR)/engines-{- $sover_dirname -}'
+     '';
+ 
+-    outputs = [ "bin" "dev" "out" "man" ] ++ optional withDocs "doc";
++    outputs = [ "bin" "dev" "out" "man" ]
++      ++ optional withDocs "doc"
++      # Separate output for the runtime dependencies of the static build.
++      ++ optional static "etc";
+     setOutputFlags = false;
+     separateDebugInfo =
+       !stdenv.hostPlatform.isDarwin &&
+@@ -101,7 +113,17 @@ let
+     configureFlags = [
+       "shared" # "shared" builds both shared and static libraries
+       "--libdir=lib"
+-      "--openssldir=etc/ssl"
++      (if !static then
++         "--openssldir=etc/ssl"
++       else
++         # Separate the OPENSSLDIR into its own output, as its path will be
++         # compiled into 'libcrypto.a'. This makes it a runtime dependency of
++         # any package that statically links openssl, so we want to keep that
++         # output minimal. We need to prepend '/.' to the path in order to make
++         # it appear absolute before variable expansion, the 'prefix' would be
++         # prepended to it otherwise.
++         "--openssldir=/.$(etc)/etc/ssl"
++      )
+     ] ++ lib.optionals withCryptodev [
+       "-DHAVE_CRYPTODEV"
+       "-DUSE_CRYPTODEV_DIGESTS"
+@@ -131,6 +153,9 @@ let
+       if [ -n "$(echo $out/lib/*.so $out/lib/*.dylib $out/lib/*.dll)" ]; then
+           rm "$out/lib/"*.a
+       fi
++
++      # 'etc' is a separate output on static builds only.
++      etc=$out
+     '' + lib.optionalString (!stdenv.hostPlatform.isWindows)
+       # Fix bin/c_rehash's perl interpreter line
+       #
+@@ -152,14 +177,15 @@ let
+       mv $out/include $dev/
+ 
+       # remove dependency on Perl at runtime
+-      rm -r $out/etc/ssl/misc
++      rm -r $etc/etc/ssl/misc
+ 
+-      rmdir $out/etc/ssl/{certs,private}
++      rmdir $etc/etc/ssl/{certs,private}
+     '';
+ 
+     postFixup = lib.optionalString (!stdenv.hostPlatform.isWindows) ''
+-      # Check to make sure the main output doesn't depend on perl
+-      if grep -r '${buildPackages.perl}' $out; then
++      # Check to make sure the main output and the static runtime dependencies
++      # don't depend on perl
++      if grep -r '${buildPackages.perl}' $out $etc; then
+         echo "Found an erroneous dependency on perl ^^^" >&2
+         exit 1
+       fi

nix/static-haskell-package.nix

@@ -0,0 +1,54 @@
+# Derive a fully static Haskell package based on musl instead of glibc.
+{ nixpkgs, compiler, patches, allOverlays }:
+
+name: src:
+let
+  # The nh2/static-haskell-nix project does all the hard work for us.
+  static-haskell-nix =
+    let
+      rev = "bd66b86b72cff4479e1c76d5916a853c38d09837";
+    in
+    builtins.fetchTarball {
+      url = "https://github.com/nh2/static-haskell-nix/archive/${rev}.tar.gz";
+      sha256 = "0rnsxaw7v27znsg9lgqk1i4007ydqrc8gfgimrmhf24lv6galbjh";
+    };
+
+  patched-static-haskell-nix =
+    patches.applyPatches "patched-static-haskell-nix"
+      static-haskell-nix
+      [
+        # No patches currently required.
+      ];
+
+  patchedNixpkgs =
+    patches.applyPatches "patched-nixpkgs"
+      nixpkgs
+      [
+        patches.nixpkgs-openssl-split-runtime-dependencies-of-static-builds
+      ];
+
+  extraOverrides =
+    final: prev:
+    rec {
+      # We need to add our package needs to the package set that we pass to
+      # static-haskell-nix. Using callCabal2nix on the haskellPackages that
+      # it returns would result in a dynamic build based on musl, and not the
+      # fully static build that we want.
+      "${name}" = prev.callCabal2nix name src { };
+    };
+
+  overlays =
+    [
+      (allOverlays.haskell-packages { inherit compiler extraOverrides; })
+    ];
+
+  # Apply our overlay to the given pkgs.
+  normalPkgs =
+    import patchedNixpkgs { inherit overlays; };
+
+  # The static-haskell-nix 'survey' derives a full static set of Haskell
+  # packages, applying fixes where necessary.
+  survey =
+    import "${patched-static-haskell-nix}/survey" { inherit normalPkgs compiler; };
+in
+survey.haskellPackages."${name}"

nix/tools/cabalTools.nix

@@ -0,0 +1,57 @@
+{ buildToolbox
+, cabal-install
+, checkedShellScript
+, devCabalOptions
+, postgrest
+}:
+let
+  build =
+    checkedShellScript
+      {
+        name = "postgrest-build";
+        docs = "Build PostgREST interactively using cabal-install.";
+        args = [ "ARG_LEFTOVERS([Cabal arguments])" ];
+        inRootDir = true;
+        withEnv = postgrest.env;
+      }
+      ''
+        exec ${cabal-install}/bin/cabal v2-build ${devCabalOptions} "''${_arg_leftovers[@]}"
+      '';
+
+  clean =
+    checkedShellScript
+      {
+        name = "postgrest-clean";
+        docs = "Clean the PostgREST project, including all cabal-install artifacts.";
+        inRootDir = true;
+      }
+      ''
+        # clean old coverage data, too
+        rm -rf .hpc coverage
+        exec ${cabal-install}/bin/cabal v2-clean
+      '';
+
+  run =
+    checkedShellScript
+      {
+        name = "postgrest-run";
+        docs = "Run PostgREST after buidling it interactively with cabal-install";
+        args = [ "ARG_LEFTOVERS([PostgREST arguments])" ];
+        inRootDir = true;
+        withEnv = postgrest.env;
+      }
+      ''
+        exec ${cabal-install}/bin/cabal v2-run ${devCabalOptions} --verbose=0 -- \
+          postgrest "''${_arg_leftovers[@]}"
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-cabal";
+  tools = [
+    build
+    clean
+    run
+  ];
+}

nix/tools/devTools.nix

@@ -0,0 +1,151 @@
+{ buildToolbox
+, cabal-install
+, cachix
+, checkedShellScript
+, devCabalOptions
+, entr
+, graphviz
+, hsie
+, nix
+, silver-searcher
+, style
+, tests
+}:
+let
+  watch =
+    checkedShellScript
+      {
+        name = "postgrest-watch";
+        docs =
+          ''
+            Watch the project for changes and reinvoke the given command.
+
+            Example:
+              postgrest-watch postgrest-test-io
+          '';
+        args =
+          [
+            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
+            "ARG_LEFTOVERS([command arguments])"
+          ];
+        addCommandCompletion = true;
+        redirectTixFiles = false; # will be done by sub-command
+        inRootDir = true;
+      }
+      ''
+        while true; do
+          (! ${silver-searcher}/bin/ag -l . | ${entr}/bin/entr -dr "$_arg_command" "''${_arg_leftovers[@]}")
+        done
+      '';
+
+  pushCachix =
+    checkedShellScript
+      {
+        name = "postgrest-push-cachix";
+        docs = ''
+          Push all build artifacts to cachix.
+
+          Requires authentication with `cachix authtoken ...`.
+        '';
+        inRootDir = true;
+      }
+      ''
+        ${nix}/bin/nix-instantiate \
+          | while read -r drv; do
+              ${nix}/bin/nix-store -qR --include-outputs "$drv"
+            done \
+          | ${cachix}/bin/cachix push postgrest
+      '';
+
+  check =
+    checkedShellScript
+      {
+        name = "postgrest-check";
+        docs =
+          ''
+            Run most checks that will also run on CI.
+
+            This currently excludes the memory tests, as those are particularly
+            expensive.
+          '';
+        inRootDir = true;
+      }
+      ''
+        ${tests}/bin/postgrest-with-all ${tests}/bin/postgrest-test-spec
+        ${tests}/bin/postgrest-test-spec-idempotence
+        ${tests}/bin/postgrest-test-io
+        ${style}/bin/postgrest-lint
+        ${style}/bin/postgrest-style-check
+      '';
+
+  dumpMinimalImports =
+    checkedShellScript
+      {
+        name = "postgrest-dump-minimal-imports";
+        docs = "Dump minimal imports into given directory.";
+        args = [ "ARG_POSITIONAL_SINGLE([dumpdir], [Output directory])" ];
+        inRootDir = true;
+        withTmpDir = true;
+      }
+      ''
+        mkdir -p "$_arg_dumpdir"
+        ${cabal-install}/bin/cabal v2-build ${devCabalOptions} \
+          --builddir="$tmpdir" \
+          --ghc-option=-ddump-minimal-imports \
+          --ghc-option=-dumpdir="$_arg_dumpdir" \
+          1>&2
+
+        # Fix OverloadedRecordFields imports
+        # shellcheck disable=SC2016
+        sed -E 's/\$sel:.*://g' -i "$_arg_dumpdir"/*
+      '';
+
+  hsieMinimalImports =
+    checkedShellScript
+      {
+        name = "postgrest-hsie-minimal-imports";
+        docs = "Run hsie with a provided dump of minimal imports.";
+        args = [ "ARG_LEFTOVERS([hsie arguments])" ];
+        withTmpDir = true;
+      }
+      ''
+        ${dumpMinimalImports} "$tmpdir"
+        ${hsie} "$tmpdir" "''${_arg_leftovers[@]}"
+      '';
+
+  hsieGraphModules =
+    checkedShellScript
+      {
+        name = "postgrest-hsie-graph-modules";
+        docs = "Create a PNG graph of modules imported within the codebase.";
+        args = [ "ARG_POSITIONAL_SINGLE([outfile], [Output filename])" ];
+      }
+      ''
+        ${hsie} graph-modules main src | ${graphviz}/bin/dot -Tpng -o "$_arg_outfile"
+      '';
+
+  hsieGraphSymbols =
+    checkedShellScript
+      {
+        name = "postgrest-hsie-graph-symbols";
+        docs = "Create a PNG graph of symbols imported within the codebase.";
+        args = [ "ARG_POSITIONAL_SINGLE([outfile], [Output filename])" ];
+      }
+      ''
+        ${hsieMinimalImports} graph-symbols | ${graphviz}/bin/dot -Tpng -o "$_arg_outfile"
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-dev";
+  tools = [
+    watch
+    pushCachix
+    check
+    dumpMinimalImports
+    hsieMinimalImports
+    hsieGraphModules
+    hsieGraphSymbols
+  ];
+}

nix/tools/docker/README.md

@@ -0,0 +1,95 @@
+# Docker image built with Nix
+
+In order to build an optimal PostgREST Docker image, we create the image from
+scratch (i.e., without a parent image like `debian` or `alpine`), and only
+include the file that is essential for running PostgREST: the static
+PostgREST binary.
+
+This is similar to what you would get with the following `Dockerfile`:
+
+```Dockerfile
+# `scratch` is a minimal, reserved image in Docker, see
+# https://docs.docker.com/develop/develop-images/baseimages/ . It essentially
+# means "don't use a parent image and start with an empty one".
+FROM scratch
+
+# The static PostgREST executable has no runtime dependencies, so it's all we
+# need to include for running the application.
+ADD /absolute/path/to/postgrest /bin/postgrest
+
+EXPOSE 3000
+
+# This is the user id that Docker will run our image under by default. Note
+# that we don't actually add the user to `/etc/passwd` or `/etc/shadow`. This
+# means that tools like whoami would not work properly, but we don't include
+# those in the image anyway. Not adding the user has the benefit that the image
+# can be run under any user you specify.
+USER 1000
+
+CMD [ "/bin/postgrest" ]
+```
+
+# Building the Docker image with Nix
+
+As we are building the static PostgREST executable with Nix and that's the main
+input to the Docker file, we can also create the Docker image directly with Nix
+using the [`dockerTools`
+utilities](https://nixos.org/nixpkgs/manual/#sec-pkgs-dockerTools). Those
+utilities don't actually use `Dockerfiles` or Docker to build Docker images,
+but create them directly by putting together the required `json` and `tar`
+files that make up an image. This is more efficient, does not rely on Docker or
+root permissions and results in fully reproducible builds. See
+[`nix/docker/default.nix`](./default.nix) for details how the image is built.
+
+# Building and loading the image
+
+The Nix expression provides a helper script `postgrest-docker-load` that loads
+the optimized image into your local Docker instance (using `docker load -i
+<image file>` under the hood). You can use it by running:
+
+```
+# Running from the root directory of the repository:
+
+# Build the `docker` attribute from `default.nix`, the result will be symlinked
+# to `result`:
+nix-build -A docker
+
+# Run the loading script:
+result/bin/postgrest-docker-load
+```
+
+The Docker image built with Nix always has the name "postgrest:latest" when
+loaded.
+
+# Inspecting the optimized image
+
+The image does not come with the usual utilities like `bash` and `ls`.
+
+You can, however, explore the `tar` file of the image by saving it with `docker
+save postgrest:latest > image.tar`.
+
+[Dive](https://github.com/wagoodman/dive) is also useful for looking at the
+contents of the image:
+
+```
+┃ ● Layers ┣━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ │ Current Layer Contents ├────────────────────────────────────────────────────────────────────────────────
+Cmp   Size  Command                                                                                        Permission     UID:GID       Size  Filetree
+     14 MB  FROM 20ee65c811575d2                                                                           dr-xr-xr-x         0:0      14 MB  ├── bin
+                                                                                                           -r-xr-xr-x         0:0      14 MB  │   └── postgrest
+│ Layer Details ├───────────────────────────────────────────────────────────────────────────────────────── drwxr-xr-x         0:0      783 B  ├── etc
+                                                                                                           -r--r--r--         0:0      783 B  │   └── postgrest.conf
+Tags:   (unavailable)                                                                                      dr-xr-xr-x         0:0      23 kB  └── nix
+Id:     20ee65c811575d206eb673e1887e7f7e6b7ccde902a63ccb924c5faa50b32cee                                   dr-xr-xr-x         0:0      23 kB      └── store
+Digest: sha256:ece77302b83fd38fb54395dabc10c2eba06fc1d1933801d36cc2c4732d9c8f38                            dr-xr-xr-x         0:0      23 kB          └── s440jbrn94wmpzy7f8yfsp6jr2shllw5-openssl-1.1.1g-etc
+Command:                                                                                                   dr-xr-xr-x         0:0      23 kB              └── etc
+                                                                                                           dr-xr-xr-x         0:0      23 kB                  └── ssl
+                                                                                                           -r--r--r--         0:0      412 B                      ├── ct_log_list.cnf
+│ Image Details ├───────────────────────────────────────────────────────────────────────────────────────── -r--r--r--         0:0      412 B                      ├── ct_log_list.cnf.dist
+                                                                                                           dr-xr-xr-x         0:0        0 B                      ├── engines-1.1
+                                                                                                           -r--r--r--         0:0      11 kB                      ├── openssl.cnf
+Total Image size: 14 MB                                                                                    -r--r--r--         0:0      11 kB                      └── openssl.cnf.dist
+Potential wasted space: 0 B
+Image efficiency score: 100 %
+
+Count   Total Space  Path
+```

nix/tools/docker/default.nix

@@ -0,0 +1,49 @@
+{ buildToolbox
+, postgrest
+, dockerTools
+, checkedShellScript
+}:
+let
+  image =
+    dockerTools.buildImage {
+      name = "postgrest";
+      tag = "latest";
+      contents = postgrest;
+
+      # Set the current time as the image creation date. This makes the build
+      # non-reproducible, but that should not be an issue for us.
+      created = "now";
+
+      extraCommands =
+        ''
+          rmdir share
+        '';
+
+      config = {
+        Cmd = [ "/bin/postgrest" ];
+        User = "1000";
+        ExposedPorts = {
+          "3000/tcp" = { };
+        };
+      };
+    };
+
+  load =
+    checkedShellScript
+      {
+        name = "postgrest-docker-load";
+        docs = "Load the PostgREST image into Docker.";
+      }
+      ''
+        docker load -i ${image}
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-docker";
+  tools = [ load ];
+  extra = {
+    inherit image;
+  };
+}

nix/tools/memory.nix

@@ -0,0 +1,29 @@
+# The memory tests have large dependencies (a profiled build of PostgREST)
+# and are run less often than the spec tests, so we don't include them in
+# the default test environment. We make them available through a separate module.
+{ buildToolbox
+, checkedShellScript
+, curl
+, postgrestProfiled
+, withTools
+}:
+let
+  test =
+    checkedShellScript
+      {
+        name = "postgrest-test-memory";
+        docs = "Run the memory tests.";
+        inRootDir = true;
+      }
+      ''
+        export PATH="${postgrestProfiled}/bin:${curl}/bin:$PATH"
+
+        ${withTools.latest} test/memory-tests.sh
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-memory";
+  tools = [ test ];
+}

nix/tools/nixpkgsTools.nix

@@ -0,0 +1,53 @@
+{ buildToolbox
+, checkedShellScript
+, curl
+, jq
+, nix
+}:
+# Utility script for pinning the latest unstable version of Nixpkgs.
+
+# Instead of pinning Nixpkgs based on the huge Git repository, we reference a
+# specific tarball that only contains the source of the revision that we want
+# to pin.
+let
+  name =
+    "postgrest-nixpkgs-upgrade";
+
+  refUrl =
+    https://api.github.com/repos/nixos/nixpkgs/git/ref/heads/nixpkgs-unstable;
+
+  githubV3Header =
+    "Accept: application/vnd.github.v3+json";
+
+  tarballUrlBase =
+    https://github.com/nixos/nixpkgs/archive/;
+
+  upgrade =
+    checkedShellScript
+      {
+        inherit name;
+        docs = "Pin the newest unstable version of Nixpkgs.";
+        inRootDir = true;
+      }
+      ''
+        commitHash="$(${curl}/bin/curl "${refUrl}" -H "${githubV3Header}" | ${jq}/bin/jq -r .object.sha)"
+        tarballUrl="${tarballUrlBase}$commitHash.tar.gz"
+        tarballHash="$(${nix}/bin/nix-prefetch-url --unpack "$tarballUrl")"
+        currentDate="$(date --iso)"
+
+        cat > nix/nixpkgs-version.nix << EOF
+        # Pinned version of Nixpkgs, generated with ${name}.
+        {
+          date = "$currentDate";
+          rev = "$commitHash";
+          tarballHash = "$tarballHash";
+        }
+        EOF
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-nixpkgs";
+  tools = [ upgrade ];
+}

nix/tools/release/default.nix

@@ -0,0 +1,174 @@
+{ buildToolbox
+, checkedShellScript
+, curl
+, docker
+, envsubst
+, ghr
+, git
+, jq
+, postgrest
+, runCommand
+}:
+let
+  github =
+    checkedShellScript
+      {
+        name = "postgrest-release-github";
+        docs = "Push a new release to GitHub.";
+        args = [
+          "ARG_POSITIONAL_SINGLE([version], [git version tag to make release for])"
+          "ARG_USE_ENV([GITHUB_TOKEN], [], [GitHub token])"
+          "ARG_USE_ENV([GITHUB_USERNAME], [], [GitHub user name])"
+          "ARG_USE_ENV([GITHUB_REPONAME], [], [GitHub repository name])"
+        ];
+        inRootDir = true;
+      }
+      ''
+        # ARG_USE_ENV only adds defaults or docs for environment variables
+        # We manually implement a required check here
+        # See also: https://github.com/matejak/argbash/issues/80
+        GITHUB_TOKEN="''${GITHUB_TOKEN:?GITHUB_TOKEN is required}"
+        GITHUB_USERNAME="''${GITHUB_USERNAME:?GITHUB_USERNAME is required}"
+        GITHUB_REPONAME="''${GITHUB_REPONAME:?GITHUB_REPONAME is required}"
+
+        if test "$_arg_version" = "nightly"
+        then
+          suffix=$(${git}/bin/git show -s --format="%cd-%h" --date="format:%Y-%m-%d-%H-%M")
+          tar cvJf "postgrest-nightly-$suffix-linux-x64-static.tar.xz" \
+            -C ${postgrest}/bin postgrest
+
+          ${ghr}/bin/ghr \
+            -t "$GITHUB_TOKEN" \
+            -u "$GITHUB_USERNAME" \
+            -r "$GITHUB_REPONAME" \
+            --replace nightly \
+            "postgrest-nightly-$suffix-linux-x64-static.tar.xz"
+        else
+          changes="$(sed -n "1,/$_arg_version/d;/## \[/q;p" ${../../../CHANGELOG.md})"
+
+          tar cvJf "postgrest-$_arg_version-linux-x64-static.tar.xz" \
+            -C ${postgrest}/bin postgrest
+
+          ${ghr}/bin/ghr \
+            -t "$GITHUB_TOKEN" \
+            -u "$GITHUB_USERNAME" \
+            -r "$GITHUB_REPONAME" \
+            -b "$changes" \
+            --replace "$_arg_version" \
+            "postgrest-$_arg_version-linux-x64-static.tar.xz"
+        fi
+      '';
+
+  dockerLogin =
+    checkedShellScript
+      {
+        name = "postgrest-release-docker-login";
+        docs =
+          ''
+            Log in to Docker Hub using the DOCKER_USER and DOCKER_PASS env vars.
+
+            Those env vars are usually provided by CircleCI. The DOCKER_USER is
+            not the same as DOCKER_REPO because we use the
+            https://hub.docker.com/u/postgrestbot account for uploading to dockerhub.
+          '';
+        args = [
+          "ARG_USE_ENV([DOCKER_USER], [], [DockerHub user name])"
+          "ARG_USE_ENV([DOCKER_PASS], [], [DockerHub password])"
+        ];
+      }
+      ''
+        # ARG_USE_ENV only adds defaults or docs for environment variables
+        # We manually implement a required check here
+        # See also: https://github.com/matejak/argbash/issues/80
+        DOCKER_USER="''${DOCKER_USER:?DOCKER_USER is required}"
+        DOCKER_PASS="''${DOCKER_PASS:?DOCKER_PASS is required}"
+
+        docker login -u "$DOCKER_USER" -p "$DOCKER_PASS"
+      '';
+
+  dockerHub =
+    checkedShellScript
+      {
+        name = "postgrest-release-dockerhub";
+        docs = "Push a new release to Docker Hub";
+        args = [
+          "ARG_POSITIONAL_SINGLE([version], [git version tag to tag image with])"
+          "ARG_USE_ENV([DOCKER_REPO], [], [DockerHub repository])"
+        ];
+      }
+      ''
+        # ARG_USE_ENV only adds defaults or docs for environment variables
+        # We manually implement a required check here
+        # See also: https://github.com/matejak/argbash/issues/80
+        DOCKER_REPO="''${DOCKER_REPO:?DOCKER_REPO is required}"
+
+        docker load -i ${docker.image}
+
+        if test "$_arg_version" = "nightly"
+        then
+          suffix=$(${git}/bin/git show -s --format="%cd-%h" --date="format:%Y-%m-%d-%H-%M")
+
+          docker tag postgrest:latest "$DOCKER_REPO/postgrest:nightly-$suffix"
+          docker push "$DOCKER_REPO/postgrest:nightly-$suffix"
+        else
+          docker tag postgrest:latest "$DOCKER_REPO"/postgrest:latest
+          docker tag postgrest:latest "$DOCKER_REPO/postgrest:$_arg_version"
+
+          docker push "$DOCKER_REPO"/postgrest:latest
+          docker push "$DOCKER_REPO/postgrest:$_arg_version"
+        fi
+      '';
+
+  dockerHubDescription =
+    let
+      description =
+        ./docker-hub-description.md;
+
+      fullDescription =
+        ./docker-hub-full-description.md;
+    in
+    checkedShellScript
+      {
+        name = "postgrest-release-dockerhub-description";
+        docs = "Update the repository description on Docker Hub.";
+        args = [
+          "ARG_USE_ENV([DOCKER_USER], [], [DockerHub user name])"
+          "ARG_USE_ENV([DOCKER_PASS], [], [DockerHub password])"
+          "ARG_USE_ENV([DOCKER_REPO], [], [DockerHub repository])"
+        ];
+      }
+      ''
+        # ARG_USE_ENV only adds defaults or docs for environment variables
+        # We manually implement a required check here
+        # See also: https://github.com/matejak/argbash/issues/80
+        DOCKER_USER="''${DOCKER_USER:?DOCKER_USER is required}"
+        DOCKER_PASS="''${DOCKER_PASS:?DOCKER_PASS is required}"
+        DOCKER_REPO="''${DOCKER_REPO:?DOCKER_REPO is required}"
+
+        # Login to Docker Hub and get a token.
+        token="$(
+          ${curl}/bin/curl -s \
+            --data-urlencode "username=$DOCKER_USER" \
+            --data-urlencode "password=$DOCKER_PASS" \
+            "https://hub.docker.com/v2/users/login/" \
+            | ${jq}/bin/jq -r .token
+        )"
+
+        # Patch both descriptions.
+        responseCode="$(
+          ${curl}/bin/curl -s --write-out "%{response_code}" \
+            --output /dev/null -H "Authorization: JWT $token" -X PATCH \
+            --data-urlencode description@${description} \
+            --data-urlencode full_description@${fullDescription} \
+            "https://hub.docker.com/v2/repositories/$DOCKER_REPO/postgrest/"
+        )"
+
+        [ "$responseCode" -eq 200 ]
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-release";
+  tools = [ github dockerLogin dockerHub dockerHubDescription ];
+}

nix/tools/release/docker-hub-description.md

@@ -0,0 +1 @@
+REST API for any Postgres database

nix/tools/release/docker-hub-full-description.md

@@ -0,0 +1,70 @@
+# PostgREST
+
+[![Join the chat at https://gitter.im/begriffs/postgrest](https://img.shields.io/badge/gitter-join%20chat%20%E2%86%92-brightgreen.svg)](https://gitter.im/begriffs/postgrest)
+[![Donate](https://img.shields.io/badge/Donate-Patreon-orange.svg?colorB=F96854)](https://www.patreon.com/postgrest)
+[![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.me/postgrest)
+[![Docs](https://img.shields.io/badge/docs-latest-brightgreen.svg?style=flat)](http://postgrest.org)
+[![Build Status](https://circleci.com/gh/PostgREST/postgrest/tree/main.svg?style=shield)](https://circleci.com/gh/PostgREST/postgrest/tree/main)
+
+PostgREST serves a fully RESTful API from any existing PostgreSQL database. It
+provides a cleaner, more standards-compliant, faster API than you are likely to
+write from scratch.
+
+## Sponsors
+
+<table>
+  <tbody>
+    <tr>
+      <td align="center" valign="middle">
+        <a href="https://www.cybertec-postgresql.com/en/?utm_source=postgrest.org&utm_medium=referral&utm_campaign=postgrest" target="_blank">
+          <img width="222px" src="https://raw.githubusercontent.com/PostgREST/postgrest/main/static/cybertec-new.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://www.2ndquadrant.com/en/?utm_campaign=External%20Websites&utm_source=PostgREST&utm_medium=Logo" target="_blank">
+          <img width="296px" src="https://raw.githubusercontent.com/PostgREST/postgrest/main/static/2ndquadrant.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://tryretool.com/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="https://raw.githubusercontent.com/PostgREST/postgrest/main/static/retool.png">
+        </a>
+      </td>
+    </tr>
+    <tr></tr>
+    <tr>
+      <td align="center" valign="middle">
+        <a href="https://gnuhost.eu/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="https://raw.githubusercontent.com/PostgREST/postgrest/main/static/gnuhost.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://supabase.io?utm_source=postgrest%20backers&utm_medium=open%20source%20partner&utm_campaign=postgrest%20backers%20github&utm_term=homepage" target="_blank">
+          <img width="296px" src="https://raw.githubusercontent.com/PostgREST/postgrest/main/static/supabase.png">
+        </a>
+      </td>
+      <td align="center" valign="middle">
+        <a href="https://oblivious.ai/?utm_source=sponsor&utm_campaign=postgrest" target="_blank">
+          <img width="296px" src="https://raw.githubusercontent.com/PostgREST/postgrest/main/static/oblivious.jpg">
+        </a>
+      </td>
+    </tr>
+  </tbody>
+</table>
+
+# Usage
+
+To learn how to use this container, see the [PostgREST Docker
+documentation](https://postgrest.com/en/stable/install.html#docker).
+
+You can configure the PostgREST image by setting
+[enviroment variables](https://postgrest.org/en/stable/configuration.html).
+
+# How this image is built
+
+The image is built from scratch using
+[Nix](https://nixos.org/nixpkgs/manual/#sec-pkgs-dockerTools) instead of a
+`Dockerfile`, which yields a higly secure and optimized image. This is also why
+no commands are listed in the image history. See the [PostgREST
+respository](https://github.com/PostgREST/postgrest/tree/main/nix/docker) for
+details on the build process and how to inspect the image.

nix/tools/style.nix

@@ -0,0 +1,68 @@
+{ black
+, buildToolbox
+, checkedShellScript
+, git
+, hlint
+, nixpkgs-fmt
+, shellcheck
+, silver-searcher
+, stylish-haskell
+}:
+let
+  style =
+    checkedShellScript
+      {
+        name = "postgrest-style";
+        docs = "Automatically format Haskell, Nix and Python files.";
+        inRootDir = true;
+      }
+      ''
+        # Format Nix files
+        ${nixpkgs-fmt}/bin/nixpkgs-fmt . > /dev/null 2> /dev/null
+
+        # Format Haskell files
+        # --vimgrep fixes a bug in ag: https://github.com/ggreer/the_silver_searcher/issues/753
+        ${silver-searcher}/bin/ag -l --vimgrep -g '\.l?hs$' . \
+          | xargs ${stylish-haskell}/bin/stylish-haskell -i
+
+        # Format Python files
+        ${black}/bin/black . 2> /dev/null
+      '';
+
+  # Script to check whether any uncommited changes result from postgrest-style
+  styleCheck =
+    checkedShellScript
+      {
+        name = "postgrest-style-check";
+        docs = "Check whether postgrest-style results in any uncommited changes.";
+        inRootDir = true;
+      }
+      ''
+        ${style}
+
+        ${git}/bin/git diff-index --exit-code HEAD -- '*.hs' '*.lhs' '*.nix'
+      '';
+
+  lint =
+    checkedShellScript
+      {
+        name = "postgrest-lint";
+        docs = "Lint all Haskell files and bash scripts.";
+        inRootDir = true;
+      }
+      ''
+        # Lint Haskell files
+        # --vimgrep fixes a bug in ag: https://github.com/ggreer/the_silver_searcher/issues/753
+        ${silver-searcher}/bin/ag -l --vimgrep -g '\.l?hs$' . \
+          | xargs ${hlint}/bin/hlint -X QuasiQuotes -X NoPatternSynonyms
+
+        # Lint bash scripts
+        ${shellcheck}/bin/shellcheck test/create_test_db test/memory-tests.sh
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-style";
+  tools = [ style styleCheck lint ];
+}

nix/tools/tests.nix

@@ -0,0 +1,173 @@
+{ buildToolbox
+, cabal-install
+, checkedShellScript
+, devCabalOptions
+, ghc
+, glibcLocales
+, gnugrep
+, haskell
+, hpc-codecov
+, jq
+, postgrest
+, python3
+, runtimeShell
+, withTools
+, yq
+}:
+let
+  testSpec =
+    checkedShellScript
+      {
+        name = "postgrest-test-spec";
+        docs = "Run the Haskell test suite";
+        inRootDir = true;
+        withEnv = postgrest.env;
+      }
+      ''
+        ${withTools.latest} ${cabal-install}/bin/cabal v2-test ${devCabalOptions}
+      '';
+
+  testSpecIdempotence =
+    checkedShellScript
+      {
+        name = "postgrest-test-spec-idempotence";
+        docs = "Check that the Haskell tests can be run multiple times against the same db.";
+        inRootDir = true;
+        withEnv = postgrest.env;
+      }
+      ''
+        ${withTools.latest} ${runtimeShell} -c " \
+          ${cabal-install}/bin/cabal v2-test ${devCabalOptions} && \
+          ${cabal-install}/bin/cabal v2-test ${devCabalOptions}"
+      '';
+
+  ioTestPython =
+    python3.withPackages (ps: [
+      ps.pyjwt
+      ps.pytest
+      ps.pytest_xdist
+      ps.pyyaml
+      ps.requests
+      ps.requests-unixsocket
+    ]);
+
+  testIO =
+    checkedShellScript
+      {
+        name = "postgrest-test-io";
+        docs = "Run the pytest-based IO tests.";
+        args = [ "ARG_LEFTOVERS([pytest arguments])" ];
+        inRootDir = true;
+        withEnv = postgrest.env;
+      }
+      ''
+        ${cabal-install}/bin/cabal v2-build ${devCabalOptions}
+        ${cabal-install}/bin/cabal v2-exec ${withTools.latest} \
+          ${ioTestPython}/bin/pytest -- -v test/io-tests "''${_arg_leftovers[@]}"
+      '';
+
+  dumpSchema =
+    checkedShellScript
+      {
+        name = "postgrest-dump-schema";
+        docs = "Dump the loaded schema's DbStructure as a yaml file.";
+        inRootDir = true;
+        withEnv = postgrest.env;
+      }
+      ''
+        export PATH="${jq}/bin:$PATH"
+        
+        ${withTools.latest} \
+            ${cabal-install}/bin/cabal v2-run ${devCabalOptions} --verbose=0 -- \
+            postgrest --dump-schema \
+            | ${yq}/bin/yq -y .
+      '';
+
+  coverage =
+    checkedShellScript
+      {
+        name = "postgrest-coverage";
+        docs = "Run spec and io tests while collecting hpc coverage data.";
+        args = [ "ARG_LEFTOVERS([hpc report arguments])" ];
+        inRootDir = true;
+        redirectTixFiles = false;
+        withEnv = postgrest.env;
+        withTmpDir = true;
+      }
+      ''
+        export LOCALE_ARCHIVE="${glibcLocales}/lib/locale/locale-archive"
+
+        # clean up previous coverage reports
+        mkdir -p coverage
+        rm -rf coverage/*
+
+        # build once before running all the tests
+        ${cabal-install}/bin/cabal v2-build ${devCabalOptions} exe:postgrest lib:postgrest test:spec test:spec-querycost
+
+        # collect all tests
+        HPCTIXFILE="$tmpdir"/io.tix \
+        ${withTools.latest} ${cabal-install}/bin/cabal v2-exec ${devCabalOptions} \
+          ${ioTestPython}/bin/pytest -- -v test/io-tests
+          
+        HPCTIXFILE="$tmpdir"/spec.tix \
+        ${withTools.latest} ${cabal-install}/bin/cabal v2-test ${devCabalOptions}
+
+        # collect all the tix files
+        ${ghc}/bin/hpc sum  --union --exclude=Paths_postgrest --output="$tmpdir"/tests.tix "$tmpdir"/io*.tix "$tmpdir"/spec.tix
+
+        # prepare the overlay
+        ${ghc}/bin/hpc overlay --output="$tmpdir"/overlay.tix test/coverage.overlay
+        ${ghc}/bin/hpc sum --union --output="$tmpdir"/tests-overlay.tix "$tmpdir"/tests.tix "$tmpdir"/overlay.tix
+
+        # check nothing in the overlay is actually tested
+        ${ghc}/bin/hpc map --function=inv --output="$tmpdir"/inverted.tix "$tmpdir"/tests.tix
+        ${ghc}/bin/hpc combine --function=sub \
+          --output="$tmpdir"/check.tix "$tmpdir"/overlay.tix "$tmpdir"/inverted.tix
+        # returns zero exit code if any count="<non-zero>" lines are found, i.e.
+        # something is covered by both the overlay and the tests
+        if ${ghc}/bin/hpc report --xml "$tmpdir"/check.tix | ${gnugrep}/bin/grep -qP 'count="[^0]'
+        then
+          ${ghc}/bin/hpc markup --highlight-covered --destdir=coverage/overlay "$tmpdir"/overlay.tix || true
+          ${ghc}/bin/hpc markup --highlight-covered --destdir=coverage/check "$tmpdir"/check.tix || true
+          echo "ERROR: Something is covered by both the tests and the overlay:"
+          echo "file://$(pwd)/coverage/check/hpc_index.html"
+          exit 1
+        else
+          # copy the result .tix file to the coverage/ dir to make it available to postgrest-coverage-draft-overlay, too
+          cp "$tmpdir"/tests-overlay.tix coverage/postgrest.tix
+          # prepare codecov json report
+          ${hpc-codecov}/bin/hpc-codecov --mix=.hpc --out=coverage/codecov.json coverage/postgrest.tix
+
+          # create html and stdout reports
+          ${ghc}/bin/hpc markup --destdir=coverage coverage/postgrest.tix
+          echo "file://$(pwd)/coverage/hpc_index.html"
+          ${ghc}/bin/hpc report coverage/postgrest.tix "''${_arg_leftovers[@]}"
+        fi
+      '';
+
+  coverageDraftOverlay =
+    checkedShellScript
+      {
+        name = "postgrest-coverage-draft-overlay";
+        docs = "Create a draft overlay from current coverage report.";
+        inRootDir = true;
+      }
+      ''
+        ${ghc}/bin/hpc draft --output=test/coverage.overlay coverage/postgrest.tix
+        sed -i 's|^module \(.*\):|module \1/|g' test/coverage.overlay
+      '';
+
+in
+buildToolbox
+{
+  name = "postgrest-tests";
+  tools =
+    [
+      testSpec
+      testSpecIdempotence
+      testIO
+      dumpSchema
+      coverage
+      coverageDraftOverlay
+    ];
+}

nix/tools/withTools.nix

@@ -0,0 +1,138 @@
+{ bashCompletion
+, buildToolbox
+, checkedShellScript
+, lib
+, postgresqlVersions
+, writeTextFile
+}:
+let
+  withTmpDb =
+    { name, postgresql }:
+    checkedShellScript
+      {
+        name = "postgrest-with-${name}";
+        docs = "Run the given command in a temporary database with ${name}";
+        args =
+          [
+            "ARG_OPTIONAL_SINGLE([fixtures], [f], [SQL file to load fixtures from], [test/fixtures/load.sql])"
+            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
+            "ARG_LEFTOVERS([command arguments])"
+            "ARG_USE_ENV([PGUSER], [postgrest_test_authenticator], [Authenticator PG role])"
+            "ARG_USE_ENV([PGDATABASE], [postgres], [PG database name])"
+            "ARG_USE_ENV([PGRST_DB_SCHEMAS], [test], [Schema to expose])"
+            "ARG_USE_ENV([PGRST_DB_ANON_ROLE], [postgrest_test_anonymous], [Anonymous PG role])"
+          ];
+        addCommandCompletion = true;
+        inRootDir = true;
+        redirectTixFiles = false;
+        withTmpDir = true;
+      }
+      ''
+        # avoid starting multiple layers of withTmpDb
+        if test -v PGRST_DB_URI; then
+          exec "$@"
+        fi
+        
+        export PATH=${postgresql}/bin:"$PATH"
+        setuplog="$tmpdir/setup.log"
+
+        log () {
+          echo "$1" >> "$setuplog"
+        }
+
+        mkdir -p "$tmpdir"/{db,socket}
+        # remove data dir, even if we keep tmpdir - no need to upload it to artifacts
+        trap 'rm -rf $tmpdir/db' EXIT
+
+        export PGDATA="$tmpdir/db"
+        export PGHOST="$tmpdir/socket"
+        export PGUSER
+        export PGDATABASE
+        export PGRST_DB_URI="postgresql:///$PGDATABASE?host=$PGHOST&user=$PGUSER"
+        export PGRST_DB_SCHEMAS
+        export PGRST_DB_ANON_ROLE
+
+        log "Initializing database cluster..."
+        # We try to make the database cluster as independent as possible from the host
+        # by specifying the timezone, locale and encoding.
+        PGTZ=UTC initdb --no-locale --encoding=UTF8 --nosync -U "$PGUSER" --auth=trust \
+          >> "$setuplog"
+
+        log "Starting the database cluster..."
+        # Instead of listening on a local port, we will listen on a unix domain socket.
+        pg_ctl -l "$tmpdir/db.log" start -o "-F -c listen_addresses=\"\" -k $PGHOST" \
+          >> "$setuplog"
+
+        log "Waiting for the database cluster to be ready..."
+        # Waiting is required for older versions of Postgres (< 10).
+        until pg_isready >> "$setuplog"; do
+          sleep 0.1
+        done
+
+        stop () {
+          log "Stopping the database cluster..."
+          pg_ctl stop -m i >> "$setuplog"
+        }
+        trap stop EXIT
+
+        log "Loading fixtures..."
+        psql -v ON_ERROR_STOP=1 -f "$_arg_fixtures" >> "$setuplog"
+
+        log "Done. Running command..."
+        ("$_arg_command" "''${_arg_leftovers[@]}")
+      '';
+
+  # Helper script for running a command against all PostgreSQL versions.
+  withAll =
+    let
+      runners =
+        builtins.map
+          (pg:
+            ''
+              cat << EOF
+
+              Running against ${pg.name}...
+
+              EOF
+
+              trap 'echo "Failed on ${pg.name}"' exit
+
+              (${withTmpDb pg} "$_arg_command" "''${_arg_leftovers[@]}")
+
+              trap "" exit
+
+              cat << EOF
+
+              Done running against ${pg.name}.
+
+              EOF
+            '')
+          postgresqlVersions;
+    in
+    checkedShellScript
+      {
+        name = "postgrest-with-all";
+        docs = "Run command against all supported PostgreSQL versions.";
+        args =
+          [
+            "ARG_POSITIONAL_SINGLE([command], [Command to run])"
+            "ARG_LEFTOVERS([command arguments])"
+          ];
+        addCommandCompletion = true;
+        inRootDir = true;
+      }
+      (lib.concatStringsSep "\n\n" runners);
+
+  # Create a `postgrest-with-postgresql-` for each PostgreSQL version
+  withVersions = builtins.map withTmpDb postgresqlVersions;
+
+in
+buildToolbox
+{
+  name = "postgrest-with";
+  tools = [ withAll ] ++ withVersions;
+  extra = {
+    # make withTools.latest available for other nix files
+    latest = withTmpDb (builtins.head postgresqlVersions);
+  };
+}

postgrest.cabal

@@ -1,159 +1,281 @@
-name:                  postgrest
-description:           Reads the schema of a PostgreSQL database and creates RESTful routes
-                       for the tables and views, supporting all HTTP verbs that security
-                       permits.
-version:               0.4.3.0
-synopsis:              REST API for any Postgres database
-license:               MIT
-license-file:          LICENSE
-author:                Joe Nelson, Adam Baker
-homepage:              https://github.com/begriffs/postgrest
-maintainer:            cred+github@begriffs.com
-category:              Web
-build-type:            Simple
-cabal-version:         >=1.10
+name:               postgrest
+version:            8.0.0
+synopsis:           REST API for any Postgres database
+description:        Reads the schema of a PostgreSQL database and creates RESTful routes
+                    for the tables and views, supporting all HTTP verbs that security
+                    permits.
+license:            MIT
+license-file:       LICENSE
+author:             Joe Nelson, Adam Baker, Steve Chavez
+maintainer:         Steve Chavez <stevechavezast@gmail.com>
+category:           Executable, PostgreSQL, Network APIs
+homepage:           https://postgrest.org
+bug-reports:        https://github.com/PostgREST/postgrest/issues
+build-type:         Simple
+extra-source-files: CHANGELOG.md
+cabal-version:      >= 1.10
+
 source-repository head
-  type: git
-  location: git://github.com/begriffs/postgrest.git
+  type:     git
+  location: git://github.com/PostgREST/postgrest.git
 
-Flag CI
-  Description: No warnings allowed in continuous integration
-  Manual:      True
-  Default:     False
+flag dev
+  default:     False
+  manual:      True
+  description: Development flags
 
-executable postgrest
-  main-is:             Main.hs
-  default-extensions:  OverloadedStrings, QuasiQuotes, NoImplicitPrelude
-  ghc-options:
-    -threaded
-    -rtsopts
-    "-with-rtsopts=-N -I2"
-  default-language:    Haskell2010
-  build-depends:       base
-                     , hasql
-                     , hasql-pool
-                     , postgrest
-                     , protolude
-                     , text
-                     , warp
-                     , bytestring
-                     , base64-bytestring
-                     , retry
-  if !os(windows)
-    build-depends:     unix
-
-  hs-source-dirs:      main
+flag hpc
+  default:     True
+  manual:      True
+  description: Enable HPC (dev only)
 
 library
+  default-language:   Haskell2010
+  default-extensions: OverloadedStrings
+                      NoImplicitPrelude
+  hs-source-dirs:     src
+  exposed-modules:    PostgREST.App
+                      PostgREST.AppState
+                      PostgREST.Auth
+                      PostgREST.CLI
+                      PostgREST.Config
+                      PostgREST.Config.Database
+                      PostgREST.Config.JSPath
+                      PostgREST.Config.PgVersion
+                      PostgREST.Config.Proxy
+                      PostgREST.ContentType
+                      PostgREST.DbStructure
+                      PostgREST.DbStructure.Identifiers
+                      PostgREST.DbStructure.Proc
+                      PostgREST.DbStructure.Relationship
+                      PostgREST.DbStructure.Table
+                      PostgREST.Error
+                      PostgREST.GucHeader
+                      PostgREST.Middleware
+                      PostgREST.OpenAPI
+                      PostgREST.Query.QueryBuilder
+                      PostgREST.Query.SqlFragment
+                      PostgREST.Query.Statements
+                      PostgREST.RangeQuery
+                      PostgREST.Request.ApiRequest
+                      PostgREST.Request.DbRequestBuilder
+                      PostgREST.Request.Parsers
+                      PostgREST.Request.Preferences
+                      PostgREST.Request.Types
+                      PostgREST.Version
+                      PostgREST.Workers
+  other-modules:      Paths_postgrest
+  build-depends:      base                      >= 4.9 && < 4.15
+                    , HTTP                      >= 4000.3.7 && < 4000.4
+                    , Ranged-sets               >= 0.3 && < 0.5
+                    , aeson                     >= 1.4.7 && < 1.6
+                    , ansi-wl-pprint            >= 0.6.7 && < 0.7
+                    , auto-update               >= 0.1.4 && < 0.2
+                    , base64-bytestring         >= 1 && < 1.3
+                    , bytestring                >= 0.10.8 && < 0.11
+                    , case-insensitive          >= 1.2 && < 1.3
+                    , cassava                   >= 0.4.5 && < 0.6
+                    , configurator-pg           >= 0.2 && < 0.3
+                    , containers                >= 0.5.7 && < 0.7
+                    , contravariant             >= 1.4 && < 1.6
+                    , contravariant-extras      >= 0.3.3 && < 0.4
+                    , cookie                    >= 0.4.2 && < 0.5
+                    , either                    >= 4.4.1 && < 5.1
+                    , fast-logger               >= 2.4.5
+                    , gitrev                    >= 1.2 && < 1.4
+                    , hasql                     >= 1.4 && < 1.5
+                    , hasql-dynamic-statements  == 0.3.1
+                    , hasql-notifications       >= 0.1 && < 0.3
+                    , hasql-pool                >= 0.5 && < 0.6
+                    , hasql-transaction         >= 1.0.1 && < 1.1
+                    , heredoc                   >= 0.2 && < 0.3
+                    , http-types                >= 0.12.2 && < 0.13
+                    , insert-ordered-containers >= 0.2.2 && < 0.3
+                    , interpolatedstring-perl6  >= 1 && < 1.1
+                    , jose                      >= 0.8.1 && < 0.9
+                    , lens                      >= 4.14 && < 5.1
+                    , lens-aeson                >= 1.0.1 && < 1.2
+                    , mtl                       >= 2.2.2 && < 2.3
+                    , network-uri               >= 2.6.1 && < 2.8
+                    , optparse-applicative      >= 0.13 && < 0.17
+                    , parsec                    >= 3.1.11 && < 3.2
+                    , protolude                 >= 0.3 && < 0.4
+                    , regex-tdfa                >= 1.2.2 && < 1.4
+                    , retry                     >= 0.7.4 && < 0.9
+                    , scientific                >= 0.3.4 && < 0.4
+                    , swagger2                  >= 2.4 && < 2.7
+                    , text                      >= 1.2.2 && < 1.3
+                    , time                      >= 1.6 && < 1.11
+                    , unordered-containers      >= 0.2.8 && < 0.3
+                    , vector                    >= 0.11 && < 0.13
+                    , wai                       >= 3.2.1 && < 3.3
+                    , wai-cors                  >= 0.2.5 && < 0.3
+                    , wai-extra                 >= 3.0.19 && < 3.2
+                    , wai-logger                >= 2.3.2
+                    , wai-middleware-static     >= 0.8.1 && < 0.10
+                    , warp                      >= 3.2.12 && < 3.4
+                      -- -fno-spec-constr may help keep compile time memory use in check,
+                      --   see https://gitlab.haskell.org/ghc/ghc/issues/16017#note_219304
+                      -- -optP-Wno-nonportable-include-path
+                      --   prevents build failures on case-insensitive filesystems (macos),
+                      --   see https://github.com/commercialhaskell/stack/issues/3918
+  ghc-options:        -Werror -Wall -fwarn-identities
+                      -fno-spec-constr -optP-Wno-nonportable-include-path
+
+  if flag(dev)
+    ghc-options: -O0
+    if flag(hpc)
+      ghc-options: -fhpc -hpcdir .hpc
+  else
+    ghc-options: -O2
+
+  if !os(windows)
+    build-depends:
+      unix
+      , directory >= 1.2.6 && < 1.4
+      , network   >= 2.6 && < 3.2
+    exposed-modules:
+      PostgREST.Unix
+
+executable postgrest
+  default-language:   Haskell2010
+  default-extensions: OverloadedStrings
+                      NoImplicitPrelude
+  hs-source-dirs:     main
+  main-is:            Main.hs
+  build-depends:      base                >= 4.9 && < 4.15
+                    , containers          >= 0.5.7 && < 0.7
+                    , postgrest
+                    , protolude           >= 0.3 && < 0.4
+  ghc-options:        -threaded -rtsopts "-with-rtsopts=-N -I2"
+                      -O2 -Werror -Wall -fwarn-identities
+                      -fno-spec-constr -optP-Wno-nonportable-include-path
+
+  if flag(dev)
+    ghc-options: -O0
+    if flag(hpc)
+      ghc-options: -fhpc -hpcdir .hpc
+  else
+    ghc-options: -O2
+
+test-suite spec
+  type:               exitcode-stdio-1.0
+  default-language:   Haskell2010
+  default-extensions: OverloadedStrings
+                      QuasiQuotes
+                      NoImplicitPrelude
+  hs-source-dirs:     test
+  main-is:            Main.hs
+  other-modules:      Feature.AndOrParamsSpec
+                      Feature.AsymmetricJwtSpec
+                      Feature.AudienceJwtSecretSpec
+                      Feature.AuthSpec
+                      Feature.BinaryJwtSecretSpec
+                      Feature.ConcurrentSpec
+                      Feature.CorsSpec
+                      Feature.DeleteSpec
+                      Feature.DisabledOpenApiSpec
+                      Feature.EmbedDisambiguationSpec
+                      Feature.ExtraSearchPathSpec
+                      Feature.HtmlRawOutputSpec
+                      Feature.InsertSpec
+                      Feature.IgnorePrivOpenApiSpec
+                      Feature.JsonOperatorSpec
+                      Feature.MultipleSchemaSpec
+                      Feature.NoJwtSpec
+                      Feature.NonexistentSchemaSpec
+                      Feature.OpenApiSpec
+                      Feature.OptionsSpec
+                      Feature.ProxySpec
+                      Feature.QueryLimitedSpec
+                      Feature.QuerySpec
+                      Feature.RangeSpec
+                      Feature.RawOutputTypesSpec
+                      Feature.RollbackSpec
+                      Feature.RootSpec
+                      Feature.RpcPreRequestGucsSpec
+                      Feature.RpcSpec
+                      Feature.SingularSpec
+                      Feature.UnicodeSpec
+                      Feature.UpdateSpec
+                      Feature.UpsertSpec
+                      SpecHelper
+                      TestTypes
+  build-depends:      base              >= 4.9 && < 4.15
+                    , aeson             >= 1.4.7 && < 1.6
+                    , aeson-qq          >= 0.8.1 && < 0.9
+                    , async             >= 2.1.1 && < 2.3
+                    , auto-update       >= 0.1.4 && < 0.2
+                    , base64-bytestring >= 1 && < 1.3
+                    , bytestring        >= 0.10.8 && < 0.11
+                    , case-insensitive  >= 1.2 && < 1.3
+                    , cassava           >= 0.4.5 && < 0.6
+                    , containers        >= 0.5.7 && < 0.7
+                    , contravariant     >= 1.4 && < 1.6
+                    , hasql             >= 1.4 && < 1.5
+                    , hasql-pool        >= 0.5 && < 0.6
+                    , hasql-transaction >= 1.0.1 && < 1.1
+                    , heredoc           >= 0.2 && < 0.3
+                    , hspec             >= 2.3 && < 2.8
+                    , hspec-wai         >= 0.10 && < 0.12
+                    , hspec-wai-json    >= 0.10 && < 0.12
+                    , http-types        >= 0.12.3 && < 0.13
+                    , lens              >= 4.14 && < 5.1
+                    , lens-aeson        >= 1.0.1 && < 1.2
+                    , monad-control     >= 1.0.1 && < 1.1
+                    , postgrest
+                    , process           >= 1.4.2 && < 1.7
+                    , protolude         >= 0.3 && < 0.4
+                    , regex-tdfa        >= 1.2.2 && < 1.4
+                    , text              >= 1.2.2 && < 1.3
+                    , time              >= 1.6 && < 1.11
+                    , transformers-base >= 0.4.4 && < 0.5
+                    , wai               >= 3.2.1 && < 3.3
+                    , wai-extra         >= 3.0.19 && < 3.2
+  ghc-options:        -O0 -Werror -Wall -fwarn-identities
+                      -fno-spec-constr -optP-Wno-nonportable-include-path
+                      -fno-warn-missing-signatures
+
+test-suite spec-querycost
+  type:                exitcode-stdio-1.0
   default-language:    Haskell2010
-  default-extensions:  OverloadedStrings, QuasiQuotes, NoImplicitPrelude
-  build-depends:       aeson
-                     , ansi-wl-pprint
-                     , base >= 4.8 && < 6
-                     , base64-bytestring
-                     , bytestring
-                     , case-insensitive
-                     , cassava
-                     , configurator-ng == 0.0.0.1
-                     , containers
-                     , contravariant
-                     , either
-                     , hasql
-                     , hasql-pool == 0.4.1
-                     , hasql-transaction == 0.5
-                     , heredoc
-                     , HTTP
-                     , http-types
-                     , insert-ordered-containers
-                     , interpolatedstring-perl6
-                     , jose
-                     , lens
-                     , lens-aeson
-                     , network-uri
-                     , optparse-applicative >= 0.13 && < 0.15
-                     , parsec
-                     , protolude >= 0.2
-                     , Ranged-sets == 0.3.0
-                     , regex-tdfa
-                     , safe
-                     , scientific
-                     , swagger2
-                     , text
-                     , unordered-containers
-                     , vector
-                     , wai
-                     , wai-cors
-                     , wai-extra
-                     , wai-middleware-static
-                     , cookie
-
-  Other-Modules:       Paths_postgrest
-  Exposed-Modules:     PostgREST.ApiRequest
-                     , PostgREST.App
-                     , PostgREST.Auth
-                     , PostgREST.Config
-                     , PostgREST.DbStructure
-                     , PostgREST.DbRequestBuilder
-                     , PostgREST.Error
-                     , PostgREST.Middleware
-                     , PostgREST.OpenAPI
-                     , PostgREST.Parsers
-                     , PostgREST.QueryBuilder
-                     , PostgREST.RangeQuery
-                     , PostgREST.Types
-  hs-source-dirs:      src
-
-Test-Suite spec
-  Type:                exitcode-stdio-1.0
-  Default-Language:    Haskell2010
-  default-extensions:  OverloadedStrings, QuasiQuotes, NoImplicitPrelude
-  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
-  Hs-Source-Dirs:      test
-  Main-Is:             Main.hs
-  Other-Modules:       Feature.AuthSpec
-                     , Feature.AsymmetricJwtSpec
-                     , Feature.BinaryJwtSecretSpec
-                     , Feature.ConcurrentSpec
-                     , Feature.CorsSpec
-                     , Feature.DeleteSpec
-                     , Feature.InsertSpec
-                     , Feature.NoJwtSpec
-                     , Feature.ProxySpec
-                     , Feature.QueryLimitedSpec
-                     , Feature.QuerySpec
-                     , Feature.RangeSpec
-                     , Feature.SingularSpec
-                     , Feature.StructureSpec
-                     , Feature.UnicodeSpec
-                     , Feature.AndOrParamsSpec
-                     , SpecHelper
-                     , TestTypes
-  Build-Depends:       aeson
-                     , aeson-qq
-                     , async
-                     , base
-                     , bytestring
-                     , base64-bytestring
-                     , case-insensitive
-                     , cassava
-                     , containers
-                     , contravariant
-                     , hasql
-                     , hasql-pool
-                     , heredoc
-                     , hjsonpointer
-                     , hjsonschema == 1.5.0.1
-                     , hspec
-                     , hspec-wai >= 0.7.0
-                     , hspec-wai-json
-                     , http-types
-                     , lens
-                     , lens-aeson
-                     , monad-control
+  default-extensions:  OverloadedStrings
+                       QuasiQuotes
+                       NoImplicitPrelude
+  hs-source-dirs:      test
+  main-is:             QueryCost.hs
+  other-modules:       SpecHelper
+  build-depends:       base              >= 4.9 && < 4.15
+                     , aeson             >= 1.4.7 && < 1.6
+                     , aeson-qq          >= 0.8.1 && < 0.9
+                     , async             >= 2.1.1 && < 2.3
+                     , auto-update       >= 0.1.4 && < 0.2
+                     , base64-bytestring >= 1 && < 1.3
+                     , bytestring        >= 0.10.8 && < 0.11
+                     , case-insensitive  >= 1.2 && < 1.3
+                     , cassava           >= 0.4.5 && < 0.6
+                     , containers        >= 0.5.7 && < 0.7
+                     , contravariant     >= 1.4 && < 1.6
+                     , hasql             >= 1.4 && < 1.5
+                     , hasql-dynamic-statements  == 0.3.1
+                     , hasql-pool        >= 0.5 && < 0.6
+                     , hasql-transaction >= 1.0.1 && < 1.1
+                     , heredoc           >= 0.2 && < 0.3
+                     , hspec             >= 2.3 && < 2.8
+                     , hspec-wai         >= 0.10 && < 0.12
+                     , hspec-wai-json    >= 0.10 && < 0.12
+                     , http-types        >= 0.12.3 && < 0.13
+                     , lens              >= 4.14 && < 5.1
+                     , lens-aeson        >= 1.0.1 && < 1.2
+                     , monad-control     >= 1.0.1 && < 1.1
                      , postgrest
-                     , process
-                     , protolude
-                     , regex-tdfa
-                     , transformers-base
-                     , wai
-                     , wai-extra
+                     , process           >= 1.4.2 && < 1.7
+                     , protolude         >= 0.3 && < 0.4
+                     , regex-tdfa        >= 1.2.2 && < 1.4
+                     , text              >= 1.2.2 && < 1.3
+                     , time              >= 1.6 && < 1.11
+                     , transformers-base >= 0.4.4 && < 0.5
+                     , wai               >= 3.2.1 && < 3.3
+                     , wai-extra         >= 3.0.19 && < 3.2
+  ghc-options:         -O0 -Werror -Wall -fwarn-identities
+                       -fno-spec-constr -optP-Wno-nonportable-include-path

scripts/release_s3.sh

@@ -1,10 +0,0 @@
-export POSTGREST_VER=`grep ^version /app/postgrest.cabal | sed -En 's/.*\s+([0-9\.]+)/\1/p'`
-
-curl -L http://sourceforge.net/projects/s3tools/files/s3cmd/1.5.0-alpha1/s3cmd-1.5.0-alpha1.tar.gz | tar zx
-
-cp /app/dist/build/postgrest/postgrest postgrest-${POSTGREST_VER}
-tar cJf postgrest-${POSTGREST_VER}.tar.xz postgrest-${POSTGREST_VER}
-
-touch ~/.s3cfg
-
-s3cmd-1.5.0-alpha1/s3cmd put --access_key=${S3_ACCESS_KEY} --secret_key=${S3_SECRET_KEY} -P -f postgrest-${POSTGREST_VER}.tar.xz $S3_BUCKET/postgrest-${POSTGREST_VER}.tar.xz

shell.nix

@@ -0,0 +1,63 @@
+# The additional modules below have large dependencies and are therefore
+# disabled by default. You can activate them by passing arguments to nix-shell,
+# e.g.:
+#
+#    nix-shell --arg release true
+#
+# This will provide you with a shell where the `postgrest-release-*` scripts
+# are available.
+#
+# We highly recommend that use the PostgREST binary cache by installing cachix
+# (https://app.cachix.org/) and running `cachix use postgrest`.
+{ docker ? false
+, memory ? false
+, release ? false
+}:
+let
+  postgrest =
+    import ./default.nix;
+
+  pkgs =
+    postgrest.pkgs;
+
+  lib =
+    pkgs.lib;
+
+  toolboxes =
+    [
+      postgrest.cabalTools
+      postgrest.devTools
+      postgrest.nixpkgsTools
+      postgrest.style
+      postgrest.tests
+      postgrest.withTools
+    ]
+    ++ lib.optional docker postgrest.docker
+    ++ lib.optional memory postgrest.memory
+    ++ lib.optional release postgrest.release;
+
+in
+lib.overrideDerivation postgrest.env (
+  base: {
+    buildInputs =
+      base.buildInputs ++ [
+        pkgs.cabal-install
+        pkgs.cabal2nix
+        pkgs.postgresql
+        postgrest.hsie.bin
+      ]
+      ++ toolboxes;
+
+    shellHook =
+      ''
+        source ${pkgs.bashCompletion}/etc/profile.d/bash_completion.sh
+        source ${postgrest.hsie.bashCompletion}
+
+      ''
+      + builtins.concatStringsSep "\n" (
+        builtins.map (bashCompletion: "source ${bashCompletion}") (
+          builtins.concatLists (builtins.map (toolbox: toolbox.bashCompletion) toolboxes)
+        )
+      );
+  }
+)

src/PostgREST/ApiRequest.hs

@@ -1,291 +0,0 @@
-{-|
-Module      : PostgREST.ApiRequest
-Description : PostgREST functions to translate HTTP request to a domain type called ApiRequest.
--}
-module PostgREST.ApiRequest ( ApiRequest(..)
-                            , ContentType(..)
-                            , Action(..)
-                            , Target(..)
-                            , PreferRepresentation (..)
-                            , mutuallyAgreeable
-                            , userApiRequest
-                            ) where
-
-import           Protolude
-import qualified Data.Aeson                as JSON
-import           Data.Aeson.Types          (emptyObject)
-import qualified Data.ByteString           as BS
-import qualified Data.ByteString.Internal  as BS (c2w)
-import qualified Data.ByteString.Lazy      as BL
-import qualified Data.Csv                  as CSV
-import qualified Data.List                 as L
-import           Data.List                 (lookup, last)
-import qualified Data.HashMap.Strict       as M
-import qualified Data.Set                  as S
-import           Data.Maybe                (fromJust)
-import           Control.Arrow             ((***))
-import qualified Data.Text                 as T
-import qualified Data.Vector               as V
-import           Network.HTTP.Base         (urlEncodeVars)
-import           Network.HTTP.Types.Header (hAuthorization, hCookie)
-import           Network.HTTP.Types.URI    (parseSimpleQuery)
-import           Network.Wai               (Request (..))
-import           Network.Wai.Parse         (parseHttpAccept)
-import           PostgREST.RangeQuery      (NonnegRange, rangeRequested, restrictRange, rangeGeq, allRange, rangeLimit, rangeOffset)
-import           Data.Ranged.Boundaries
-import           PostgREST.Types           ( QualifiedIdentifier (..)
-                                           , Schema
-                                           , PayloadJSON(..)
-                                           , ContentType(..)
-                                           , ApiRequestError(..)
-                                           , toMime)
-import           Data.Ranged.Ranges        (Range(..), rangeIntersection, emptyRange)
-import qualified Data.CaseInsensitive      as CI
-import           Web.Cookie                (parseCookiesText)
-
-type RequestBody = BL.ByteString
-
--- | Types of things a user wants to do to tables/views/procs
-data Action = ActionCreate | ActionRead
-            | ActionUpdate | ActionDelete
-            | ActionInfo   | ActionInvoke
-            | ActionInspect
-            deriving Eq
--- | The target db object of a user action
-data Target = TargetIdent QualifiedIdentifier
-            | TargetProc  QualifiedIdentifier
-            | TargetRoot
-            | TargetUnknown [Text]
-            deriving Eq
--- | How to return the inserted data
-data PreferRepresentation = Full | HeadersOnly | None deriving Eq
-                          --
-{-|
-  Describes what the user wants to do. This data type is a
-  translation of the raw elements of an HTTP request into domain
-  specific language.  There is no guarantee that the intent is
-  sensible, it is up to a later stage of processing to determine
-  if it is an action we are able to perform.
--}
-data ApiRequest = ApiRequest {
-  -- | Similar but not identical to HTTP verb, e.g. Create/Invoke both POST
-    iAction :: Action
-  -- | Requested range of rows within response
-  , iRange  :: M.HashMap ByteString NonnegRange
-  -- | The target, be it calling a proc or accessing a table
-  , iTarget :: Target
-  -- | Content types the client will accept, [CTAny] if no Accept header
-  , iAccepts :: [ContentType]
-  -- | Data sent by client and used for mutation actions
-  , iPayload :: Maybe PayloadJSON
-  -- | If client wants created items echoed back
-  , iPreferRepresentation :: PreferRepresentation
-  -- | Pass all parameters as a single json object to a stored procedure
-  , iPreferSingleObjectParameter :: Bool
-  -- | Whether the client wants a result count (slower)
-  , iPreferCount :: Bool
-  -- | Filters on the result ("id", "eq.10")
-  , iFilters :: [(Text, Text)]
-  -- | &and and &or parameters used for complex boolean logic
-  , iLogic :: [(Text, Text)]
-  -- | &select parameter used to shape the response
-  , iSelect :: Text
-  -- | &order parameters for each level
-  , iOrder :: [(Text, Text)]
-  -- | Alphabetized (canonical) request query string for response URLs
-  , iCanonicalQS :: ByteString
-  -- | JSON Web Token
-  , iJWT :: Text
-  -- | HTTP request headers
-  , iHeaders :: [(Text, Text)]
-  -- | Request Cookies
-  , iCookies :: [(Text, Text)]
-  }
-
--- | Examines HTTP request and translates it into user intent.
-userApiRequest :: Schema -> Request -> RequestBody -> Either ApiRequestError ApiRequest
-userApiRequest schema req reqBody
-  | isTargetingProc && method /= "POST" = Left ActionInappropriate
-  | topLevelRange == emptyRange = Left InvalidRange
-  | shouldParsePayload && isLeft payload = either (Left . InvalidBody . toS) undefined payload
-  | otherwise = Right ApiRequest {
-      iAction = action
-      , iTarget = target
-      , iRange = ranges
-      , iAccepts = fromMaybe [CTAny] $
-        map decodeContentType . parseHttpAccept <$> lookupHeader "accept"
-      , iPayload = relevantPayload
-      , iPreferRepresentation = representation
-      , iPreferSingleObjectParameter = singleObject
-      , iPreferCount = hasPrefer "count=exact"
-      , iFilters = [ (toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, k /= "select", not (endingIn ["order", "limit", "offset", "and", "or"] k) ]
-      , iLogic = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["and", "or"] k ]
-      , iSelect = toS $ fromMaybe "*" $ fromMaybe (Just "*") $ lookup "select" qParams
-      , iOrder = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["order"] k ]
-      , iCanonicalQS = toS $ urlEncodeVars
-        . L.sortBy (comparing fst)
-        . map (join (***) toS)
-        . parseSimpleQuery
-        $ rawQueryString req
-      , iJWT = tokenStr
-      , iHeaders = [ (toS $ CI.foldedCase k, toS v) | (k,v) <- hdrs, k /= hAuthorization, k /= hCookie]
-      , iCookies = fromMaybe [] $ parseCookiesText <$> lookupHeader "Cookie"
-      }
- where
-  isTargetingProc = fromMaybe False $ (== "rpc") <$> listToMaybe path
-  payload =
-    case decodeContentType . fromMaybe "application/json" $ lookupHeader "content-type" of
-      CTApplicationJSON ->
-        note "All object keys must match" . ensureUniform . pluralize
-          =<< if BL.null reqBody && isTargetingProc
-               then Right emptyObject
-               else JSON.eitherDecode reqBody
-      CTTextCSV ->
-        note "All lines must have same number of fields" . ensureUniform . csvToJson
-          =<< CSV.decodeByName reqBody
-      CTOther "application/x-www-form-urlencoded" ->
-        Right . PayloadJSON . V.singleton . M.fromList
-                    . map (toS *** JSON.String . toS) . parseSimpleQuery
-                    $ toS reqBody
-      ct ->
-        Left $ toS $ "Content-Type not acceptable: " <> toMime ct
-  topLevelRange = fromMaybe allRange $ M.lookup "limit" ranges
-  action = case method of
-            "GET"     -> if target == TargetRoot
-                          then ActionInspect
-                          else ActionRead
-            "POST"    -> if isTargetingProc
-                          then ActionInvoke
-                          else ActionCreate
-            "PATCH"   -> ActionUpdate
-            "DELETE"  -> ActionDelete
-            "OPTIONS" -> ActionInfo
-            _         -> ActionInspect
-  target = case path of
-              []            -> TargetRoot
-              [table]       -> TargetIdent
-                              $ QualifiedIdentifier schema table
-              ["rpc", proc] -> TargetProc
-                              $ QualifiedIdentifier schema proc
-              other         -> TargetUnknown other
-  shouldParsePayload = action `elem` [ActionCreate, ActionUpdate, ActionInvoke]
-  relevantPayload = if shouldParsePayload
-                      then rightToMaybe payload
-                      else Nothing
-  path            = pathInfo req
-  method          = requestMethod req
-  hdrs            = requestHeaders req
-  qParams         = [(toS k, v)|(k,v) <- queryString req]
-  lookupHeader    = flip lookup hdrs
-  hasPrefer :: Text -> Bool
-  hasPrefer val   = any (\(h,v) -> h == "Prefer" && val `elem` split v) hdrs
-    where
-        split :: BS.ByteString -> [Text]
-        split = map T.strip . T.split (==',') . toS
-  singleObject    = hasPrefer "params=single-object"
-  representation
-    | hasPrefer "return=representation" = Full
-    | hasPrefer "return=minimal" = None
-    | otherwise = HeadersOnly
-  auth = fromMaybe "" $ lookupHeader hAuthorization
-  tokenStr = case T.split (== ' ') (toS auth) of
-    ("Bearer" : t : _) -> t
-    _                  -> ""
-  endingIn:: [Text] -> Text -> Bool
-  endingIn xx key = lastWord `elem` xx
-    where lastWord = last $ T.split (=='.') key
-
-  headerRange = rangeRequested hdrs
-  replaceLast x s = T.intercalate "." $ L.init (T.split (=='.') s) ++ [x]
-  limitParams :: M.HashMap ByteString NonnegRange
-  limitParams  = M.fromList [(toS (replaceLast "limit" k), restrictRange (readMaybe =<< (toS <$> v)) allRange) | (k,v) <- qParams, isJust v, endingIn ["limit"] k]
-  offsetParams :: M.HashMap ByteString NonnegRange
-  offsetParams = M.fromList [(toS (replaceLast "limit" k), fromMaybe allRange (rangeGeq <$> (readMaybe =<< (toS <$> v)))) | (k,v) <- qParams, isJust v, endingIn ["offset"] k]
-
-  urlRange = M.unionWith f limitParams offsetParams
-    where
-      f rl ro = Range (BoundaryBelow o) (BoundaryAbove $ o + l - 1)
-        where
-          l = fromMaybe 0 $ rangeLimit rl
-          o = rangeOffset ro
-  ranges = M.insert "limit" (rangeIntersection headerRange (fromMaybe allRange (M.lookup "limit" urlRange))) urlRange
-
-{-|
-  Find the best match from a list of content types accepted by the
-  client in order of decreasing preference and a list of types
-  producible by the server.  If there is no match but the client
-  accepts */* then return the top server pick.
--}
-mutuallyAgreeable :: [ContentType] -> [ContentType] -> Maybe ContentType
-mutuallyAgreeable sProduces cAccepts =
-  let exact = listToMaybe $ L.intersect cAccepts sProduces in
-  if isNothing exact && CTAny `elem` cAccepts
-     then listToMaybe sProduces
-     else exact
-
--- PRIVATE ---------------------------------------------------------------
-
-{-|
-  Warning: discards MIME parameters
--}
-decodeContentType :: BS.ByteString -> ContentType
-decodeContentType ct =
-  case BS.takeWhile (/= BS.c2w ';') ct of
-    "application/json"                  -> CTApplicationJSON
-    "text/csv"                          -> CTTextCSV
-    "application/openapi+json"          -> CTOpenAPI
-    "application/vnd.pgrst.object+json" -> CTSingularJSON
-    "application/vnd.pgrst.object"      -> CTSingularJSON
-    "application/octet-stream"          -> CTOctetStream
-    "*/*"                               -> CTAny
-    ct'                                 -> CTOther ct'
-
-type CsvData = V.Vector (M.HashMap Text BL.ByteString)
-
-{-|
-  Converts CSV like
-  a,b
-  1,hi
-  2,bye
-
-  into a JSON array like
-  [ {"a": "1", "b": "hi"}, {"a": 2, "b": "bye"} ]
-
-  The reason for its odd signature is so that it can compose
-  directly with CSV.decodeByName
--}
-csvToJson :: (CSV.Header, CsvData) -> JSON.Array
-csvToJson (_, vals) =
-  V.map rowToJsonObj vals
- where
-  rowToJsonObj = JSON.Object .
-    M.map (\str ->
-        if str == "NULL"
-          then JSON.Null
-          else JSON.String $ toS str
-      )
-
--- | Convert {foo} to [{foo}], leave arrays unchanged
--- and truncate everything else to an empty array.
-pluralize :: JSON.Value -> JSON.Array
-pluralize obj@(JSON.Object _) = V.singleton obj
-pluralize (JSON.Array arr)    = arr
-pluralize _                   = V.empty
-
--- | Test that Array contains only Objects having the same keys
--- and if so mark it as PayloadJSON
-ensureUniform :: JSON.Array -> Maybe PayloadJSON
-ensureUniform arr =
-  let objs :: V.Vector JSON.Object
-      objs = foldr -- filter non-objects, map to raw objects
-               (\val result -> case val of
-                  JSON.Object o -> V.cons o result
-                  _ -> result)
-               V.empty arr
-      keysPerObj = V.map (S.fromList . M.keys) objs
-      canonicalKeys = fromMaybe S.empty $ keysPerObj V.!? 0
-      areKeysUniform = all (==canonicalKeys) keysPerObj in
-
-  if (V.length objs == V.length arr) && areKeysUniform
-    then Just (PayloadJSON objs)
-    else Nothing

src/PostgREST/App.hs

@@ -1,364 +1,616 @@
-{-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE ScopedTypeVariables #-}
+{-|
+Module      : PostgREST.App
+Description : PostgREST main application
 
-module PostgREST.App (
-  postgrest
-) where
+This module is in charge of mapping HTTP requests to PostgreSQL queries.
+Some of its functionality includes:
 
-import           Control.Applicative
-import qualified Data.ByteString.Char8     as BS
-import           Data.Maybe
-import           Data.IORef                (IORef, readIORef)
-import           Data.Text                 (intercalate)
+- Mapping HTTP request methods to proper SQL statements. For example, a GET request is translated to executing a SELECT query in a read-only TRANSACTION.
+- Producing HTTP Headers according to RFCs.
+- Content Negotiation
+-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.App
+  ( SignalHandlerInstaller
+  , SocketRunner
+  , postgrest
+  , run
+  ) where
 
-import qualified Hasql.Pool                 as P
-import qualified Hasql.Transaction          as HT
-import qualified Hasql.Transaction.Sessions as HT
+import Control.Monad.Except     (liftEither)
+import Data.Either.Combinators  (mapLeft)
+import Data.List                (union)
+import Data.String              (IsString (..))
+import Data.Time.Clock          (UTCTime)
+import Network.Wai.Handler.Warp (defaultSettings, setHost, setPort,
+                                 setServerName)
+import System.Posix.Types       (FileMode)
 
-import           Network.HTTP.Types.Header
-import           Network.HTTP.Types.Status
-import           Network.HTTP.Types.URI    (renderSimpleQuery)
-import           Network.Wai
-import           Network.Wai.Middleware.RequestLogger (logStdout)
+import qualified Data.ByteString.Char8           as BS8
+import qualified Data.ByteString.Lazy            as LBS
+import qualified Data.HashMap.Strict             as Map
+import qualified Data.Set                        as Set
+import qualified Hasql.DynamicStatements.Snippet as SQL
+import qualified Hasql.Pool                      as SQL
+import qualified Hasql.Transaction               as SQL
+import qualified Hasql.Transaction.Sessions      as SQL
+import qualified Network.HTTP.Types.Header       as HTTP
+import qualified Network.HTTP.Types.Status       as HTTP
+import qualified Network.HTTP.Types.URI          as HTTP
+import qualified Network.Wai                     as Wai
+import qualified Network.Wai.Handler.Warp        as Warp
 
-import qualified Data.Vector               as V
-import qualified Hasql.Transaction         as H
+import qualified PostgREST.AppState                 as AppState
+import qualified PostgREST.Auth                     as Auth
+import qualified PostgREST.DbStructure              as DbStructure
+import qualified PostgREST.Error                    as Error
+import qualified PostgREST.Middleware               as Middleware
+import qualified PostgREST.OpenAPI                  as OpenAPI
+import qualified PostgREST.Query.QueryBuilder       as QueryBuilder
+import qualified PostgREST.Query.Statements         as Statements
+import qualified PostgREST.RangeQuery               as RangeQuery
+import qualified PostgREST.Request.ApiRequest       as ApiRequest
+import qualified PostgREST.Request.DbRequestBuilder as ReqBuilder
 
-import qualified Data.HashMap.Strict       as M
+import PostgREST.AppState                (AppState)
+import PostgREST.Config                  (AppConfig (..),
+                                          LogLevel (..),
+                                          OpenAPIMode (..))
+import PostgREST.Config.PgVersion        (PgVersion (..))
+import PostgREST.ContentType             (ContentType (..))
+import PostgREST.DbStructure             (DbStructure (..),
+                                          tablePKCols)
+import PostgREST.DbStructure.Identifiers (FieldName,
+                                          QualifiedIdentifier (..),
+                                          Schema)
+import PostgREST.DbStructure.Proc        (ProcDescription (..),
+                                          ProcVolatility (..))
+import PostgREST.DbStructure.Table       (Table (..))
+import PostgREST.Error                   (Error)
+import PostgREST.GucHeader               (GucHeader,
+                                          addHeadersIfNotIncluded,
+                                          unwrapGucHeader)
+import PostgREST.Request.ApiRequest      (Action (..),
+                                          ApiRequest (..),
+                                          InvokeMethod (..),
+                                          Target (..))
+import PostgREST.Request.Preferences     (PreferCount (..),
+                                          PreferParameters (..),
+                                          PreferRepresentation (..))
+import PostgREST.Request.Types           (ReadRequest, fstFieldNames)
+import PostgREST.Version                 (prettyVersion)
+import PostgREST.Workers                 (connectionWorker, listener)
 
-import           PostgREST.ApiRequest   ( ApiRequest(..), ContentType(..)
-                                        , Action(..), Target(..)
-                                        , PreferRepresentation (..)
-                                        , mutuallyAgreeable
-                                        , userApiRequest
-                                        )
-import           PostgREST.Auth            (jwtClaims, containsRole, parseJWK)
-import           PostgREST.Config          (AppConfig (..))
-import           PostgREST.DbStructure
-import           PostgREST.DbRequestBuilder( readRequest
-                                           , mutateRequest
-                                           , fieldNames
-                                           )
-import           PostgREST.Error           ( simpleError, pgError
-                                           , apiRequestError
-                                           , singularityError, binaryFieldError
-                                           , connectionLostError
-                                           )
-import           PostgREST.RangeQuery      (allRange, rangeOffset)
-import           PostgREST.Middleware
-import           PostgREST.QueryBuilder ( callProc
-                                        , requestToQuery
-                                        , requestToCountQuery
-                                        , createReadStatement
-                                        , createWriteStatement
-                                        , ResultsWithCount
-                                        )
-import           PostgREST.Types
-import           PostgREST.OpenAPI
+import qualified PostgREST.ContentType      as ContentType
+import qualified PostgREST.DbStructure.Proc as Proc
 
-import           Data.Function (id)
-import           Protolude              hiding (intercalate, Proxy)
-import           Safe                   (headMay)
+import Protolude      hiding (Handler, toS)
+import Protolude.Conv (toS)
 
-postgrest :: AppConfig -> IORef (Maybe DbStructure) -> P.Pool -> IO () -> Application
-postgrest conf refDbStructure pool worker =
-  let middle = (if configQuiet conf then id else logStdout) . defaultMiddle
-      jwtSecret = parseJWK <$> configJwtSecret conf in
 
-  middle $ \ req respond -> do
-    body <- strictRequestBody req
-    maybeDbStructure <- readIORef refDbStructure
+data RequestContext = RequestContext
+  { ctxConfig      :: AppConfig
+  , ctxDbStructure :: DbStructure
+  , ctxApiRequest  :: ApiRequest
+  , ctxPgVersion   :: PgVersion
+  }
+
+type Handler = ExceptT Error
+
+type DbHandler = Handler SQL.Transaction
+
+type SignalHandlerInstaller = AppState -> IO()
+
+type SocketRunner = Warp.Settings -> Wai.Application -> FileMode -> FilePath -> IO()
+
+
+run :: SignalHandlerInstaller -> Maybe SocketRunner -> AppState -> IO ()
+run installHandlers maybeRunWithSocket appState = do
+  conf@AppConfig{..} <- AppState.getConfig appState
+  connectionWorker appState -- Loads the initial DbStructure
+  installHandlers appState
+  -- reload schema cache + config on NOTIFY
+  when configDbChannelEnabled $ listener appState
+
+  let app = postgrest configLogLevel appState (connectionWorker appState)
+
+  case configServerUnixSocket of
+    Just socket ->
+      -- run the postgrest application with user defined socket. Only for UNIX systems
+      case maybeRunWithSocket of
+        Just runWithSocket -> do
+          AppState.logWithZTime appState $ "Listening on unix socket " <> show socket
+          runWithSocket (serverSettings conf) app configServerUnixSocketMode socket
+        Nothing ->
+          panic "Cannot run with socket on non-unix plattforms."
+    Nothing ->
+      do
+        AppState.logWithZTime appState $ "Listening on port " <> show configServerPort
+        Warp.runSettings (serverSettings conf) app
+
+serverSettings :: AppConfig -> Warp.Settings
+serverSettings AppConfig{..} =
+  defaultSettings
+    & setHost (fromString $ toS configServerHost)
+    & setPort configServerPort
+    & setServerName (toS $ "postgrest/" <> prettyVersion)
+
+-- | PostgREST application
+postgrest :: LogLevel -> AppState.AppState -> IO () -> Wai.Application
+postgrest logLev appState connWorker =
+  Middleware.pgrstMiddleware logLev $
+    \req respond -> do
+      time <- AppState.getTime appState
+      conf <- AppState.getConfig appState
+      maybeDbStructure <- AppState.getDbStructure appState
+      pgVer <- AppState.getPgVersion appState
+      jsonDbS <- AppState.getJsonDbS appState
+
+      let
+        eitherResponse :: IO (Either Error Wai.Response)
+        eitherResponse =
+          runExceptT $ postgrestResponse conf maybeDbStructure jsonDbS pgVer (AppState.getPool appState) time req
+
+      response <- either Error.errorResponseFor identity <$> eitherResponse
+
+      -- Launch the connWorker when the connection is down.  The postgrest
+      -- function can respond successfully (with a stale schema cache) before
+      -- the connWorker is done.
+      when (Wai.responseStatus response == HTTP.status503) connWorker
+
+      respond response
+
+postgrestResponse
+  :: AppConfig
+  -> Maybe DbStructure
+  -> ByteString
+  -> PgVersion
+  -> SQL.Pool
+  -> UTCTime
+  -> Wai.Request
+  -> Handler IO Wai.Response
+postgrestResponse conf maybeDbStructure jsonDbS pgVer pool time req = do
+  body <- lift $ Wai.strictRequestBody req
+
+  dbStructure <-
     case maybeDbStructure of
-      Nothing -> respond connectionLostError
-      Just dbStructure -> do
-        response <- case userApiRequest (configSchema conf) req body of
-          Left err -> return $ apiRequestError err
-          Right apiRequest -> do
-            eClaims <- jwtClaims jwtSecret (toS $ iJWT apiRequest)
+      Just dbStructure ->
+        return dbStructure
+      Nothing ->
+        throwError Error.ConnectionLostError
 
-            let authed = containsRole eClaims
-                handleReq = runWithClaims conf eClaims (app dbStructure conf) apiRequest
-                txMode = transactionMode dbStructure
-                  (iTarget apiRequest) (iAction apiRequest)
-            response <- P.use pool $ HT.transaction HT.ReadCommitted txMode handleReq
-            return $ either (pgError authed) identity response
-        when (isResponse503 response) worker
-        respond response
+  apiRequest@ApiRequest{..} <-
+    liftEither . mapLeft Error.ApiRequestError $
+      ApiRequest.userApiRequest conf dbStructure req body
 
-isResponse503 :: Response -> Bool
-isResponse503 resp = statusCode (responseStatus resp) == 503
+  -- The JWT must be checked before touching the db
+  jwtClaims <- Auth.jwtClaims conf (toS iJWT) time
 
-transactionMode :: DbStructure -> Target -> Action -> H.Mode
-transactionMode structure target action =
-  case action of
-    ActionRead -> HT.Read
-    ActionInfo -> HT.Read
-    ActionInspect -> HT.Read
-    ActionInvoke ->
-      let proc =
-            case target of
-              (TargetProc qi) -> M.lookup (qiName qi) $
-                                   dbProcs structure
-              _               -> Nothing
-          v = fromMaybe Volatile $ pdVolatility <$> proc in
-      if v == Stable || v == Immutable
-         then HT.Read
-         else HT.Write
-    _ -> HT.Write
+  let
+    handleReq apiReq =
+      handleRequest $ RequestContext conf dbStructure apiReq pgVer
 
-app :: DbStructure -> AppConfig -> ApiRequest -> H.Transaction Response
-app dbStructure conf apiRequest =
-  case responseContentTypeOrError (iAccepts apiRequest) (iAction apiRequest) of
-    Left errorResponse -> return errorResponse
-    Right contentType ->
-      case (iAction apiRequest, iTarget apiRequest, iPayload apiRequest) of
+  runDbHandler pool (txMode apiRequest) jwtClaims (configDbPreparedStatements conf) .
+    Middleware.optionalRollback conf apiRequest $
+      Middleware.runPgLocals conf jwtClaims handleReq apiRequest jsonDbS
 
-        (ActionRead, TargetIdent qi, Nothing) ->
-          let partsField = (,) <$> readSqlParts
-                <*> (binaryField contentType =<< fldNames) in
-          case partsField of
-            Left errorResponse -> return errorResponse
-            Right ((q, cq), bField) -> do
-              let stm = createReadStatement q cq (contentType == CTSingularJSON) shouldCount
-                                            (contentType == CTTextCSV) bField
-              row <- H.query () stm
-              let (tableTotal, queryTotal, _ , body) = row
-                  (status, contentRange) = rangeHeader queryTotal tableTotal
-                  canonical = iCanonicalQS apiRequest
-              return $
-                if contentType == CTSingularJSON && queryTotal /= 1
-                  then singularityError (toInteger queryTotal)
-                  else responseLBS status
-                    [toHeader contentType, contentRange,
-                      ("Content-Location",
-                        "/" <> toS (qiName qi) <>
-                          if BS.null canonical then "" else "?" <> toS canonical
-                      )
-                    ] (toS body)
+runDbHandler :: SQL.Pool -> SQL.Mode -> Auth.JWTClaims -> Bool -> DbHandler a -> Handler IO a
+runDbHandler pool mode jwtClaims prepared handler = do
+  dbResp <-
+    let transaction = if prepared then SQL.transaction else SQL.unpreparedTransaction in
+    lift . SQL.use pool . transaction SQL.ReadCommitted mode $ runExceptT handler
 
-        (ActionCreate, TargetIdent (QualifiedIdentifier _ table), Just payload@(PayloadJSON rows)) ->
-          case mutateSqlParts of
-            Left errorResponse -> return errorResponse
-            Right (sq, mq) -> do
-              let isSingle = (==1) $ V.length rows
-              if contentType == CTSingularJSON
-                 && not isSingle
-                 && iPreferRepresentation apiRequest == Full
-                then return $ singularityError (toInteger $ V.length rows)
-                else do
-                  let pKeys = map pkName $ filter (filterPk schema table) allPrKeys -- would it be ok to move primary key detection in the query itself?
-                      stm = createWriteStatement sq mq
-                        (contentType == CTSingularJSON) isSingle
-                        (contentType == CTTextCSV) (iPreferRepresentation apiRequest)
-                        pKeys
-                  row <- H.query payload stm
-                  let (_, _, fs, body) = extractQueryResult row
-                      headers = catMaybes [
-                          if null fs
-                            then Nothing
-                            else Just (hLocation, "/" <> toS table <> renderLocationFields fs)
-                        , if iPreferRepresentation apiRequest == Full
-                            then Just $ toHeader contentType
-                            else Nothing
-                        , Just . contentRangeH 1 0 $
-                            toInteger <$> if shouldCount then Just (V.length rows) else Nothing
-                        ]
+  resp <-
+    liftEither . mapLeft Error.PgErr $
+      mapLeft (Error.PgError $ Auth.containsRole jwtClaims) dbResp
 
-                  return . responseLBS status201 headers $
-                    if iPreferRepresentation apiRequest == Full
-                      then toS body else ""
+  liftEither resp
 
-        (ActionUpdate, TargetIdent _, Just payload@(PayloadJSON rows)) ->
-          case (mutateSqlParts, null <$> rows V.!? 0, iPreferRepresentation apiRequest == Full) of
-            (Left errorResponse, _, _) -> return errorResponse
-            (_, Just True, True) -> return $ responseLBS status200 [contentRangeH 1 0 Nothing] "[]"
-            (_, Just True, False) -> return $ responseLBS status204 [contentRangeH 1 0 Nothing] ""
-            (Right (sq, mq), _, _) -> do
-              let stm = createWriteStatement sq mq
-                    (contentType == CTSingularJSON) False (contentType == CTTextCSV)
-                    (iPreferRepresentation apiRequest) []
-              row <- H.query payload stm
-              let (_, queryTotal, _, body) = extractQueryResult row
-              if contentType == CTSingularJSON
-                 && queryTotal /= 1
-                 && iPreferRepresentation apiRequest == Full
-                then do
-                  HT.condemn
-                  return $ singularityError (toInteger queryTotal)
-                else do
-                  let r = contentRangeH 0 (toInteger $ queryTotal-1)
-                            (toInteger <$> if shouldCount then Just queryTotal else Nothing)
-                      s = if iPreferRepresentation apiRequest == Full
-                            then status200
-                            else status204
-                  return $ if iPreferRepresentation apiRequest == Full
-                    then responseLBS s [toHeader contentType, r] (toS body)
-                    else responseLBS s [r] ""
+handleRequest :: RequestContext -> DbHandler Wai.Response
+handleRequest context@(RequestContext _ _ ApiRequest{..} _) =
+  case (iAction, iTarget) of
+    (ActionRead headersOnly, TargetIdent identifier) ->
+      handleRead headersOnly identifier context
+    (ActionCreate, TargetIdent identifier) ->
+      handleCreate identifier context
+    (ActionUpdate, TargetIdent identifier) ->
+      handleUpdate identifier context
+    (ActionSingleUpsert, TargetIdent identifier) ->
+      handleSingleUpsert identifier context
+    (ActionDelete, TargetIdent identifier) ->
+      handleDelete identifier context
+    (ActionInfo, TargetIdent identifier) ->
+      handleInfo identifier context
+    (ActionInvoke invMethod, TargetProc proc _) ->
+      handleInvoke invMethod proc context
+    (ActionInspect headersOnly, TargetDefaultSpec tSchema) ->
+      handleOpenApi headersOnly tSchema context
+    _ ->
+      throwError Error.NotFound
 
-        (ActionDelete, TargetIdent _, Nothing) ->
-          case mutateSqlParts of
-            Left errorResponse -> return errorResponse
-            Right (sq, mq) -> do
-              let emptyPayload = PayloadJSON V.empty
-                  stm = createWriteStatement sq mq
-                    (contentType == CTSingularJSON) False
-                    (contentType == CTTextCSV)
-                    (iPreferRepresentation apiRequest) []
-              row <- H.query emptyPayload stm
-              let (_, queryTotal, _, body) = extractQueryResult row
-                  r = contentRangeH 1 0 $
-                        toInteger <$> if shouldCount then Just queryTotal else Nothing
-              if contentType == CTSingularJSON
-                 && queryTotal /= 1
-                 && iPreferRepresentation apiRequest == Full
-                then do
-                  HT.condemn
-                  return $ singularityError (toInteger queryTotal)
-                else
-                  return $ if iPreferRepresentation apiRequest == Full
-                    then responseLBS status200 [toHeader contentType, r] (toS body)
-                    else responseLBS status204 [r] ""
+handleRead :: Bool -> QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleRead headersOnly identifier context@RequestContext{..} = do
+  req <- readRequest identifier context
+  bField <- binaryField context req
 
-        (ActionInfo, TargetIdent (QualifiedIdentifier tSchema tTable), Nothing) ->
-          let mTable = find (\t -> tableName t == tTable && tableSchema t == tSchema) (dbTables dbStructure) in
-          case mTable of
-            Nothing -> return notFound
-            Just table ->
-              let acceptH = (hAllow, if tableInsertable table then "GET,POST,PATCH,DELETE" else "GET") in
-              return $ responseLBS status200 [allOrigins, acceptH] ""
+  let
+    ApiRequest{..} = ctxApiRequest
+    AppConfig{..} = ctxConfig
+    countQuery = QueryBuilder.readRequestToCountQuery req
 
-        (ActionInvoke, TargetProc qi, Just (PayloadJSON payload)) ->
-          let proc = M.lookup (qiName qi) allProcs
-              returnsScalar = case proc of
-                Just ProcDescription{pdReturnType = (Single (Scalar _))} -> True
-                _ -> False
-              rpcBinaryField = if returnsScalar
-                                 then Right Nothing
-                                 else binaryField contentType =<< fldNames
-              partsField = (,) <$> readSqlParts <*> rpcBinaryField in
-          case partsField of
-            Left errorResponse -> return errorResponse
-            Right ((q, cq), bField) -> do
-              let p = V.head payload
-                  singular = contentType == CTSingularJSON
-                  paramsAsSingleObject = iPreferSingleObjectParameter apiRequest
-              row <- H.query () $
-                callProc qi p returnsScalar q cq topLevelRange shouldCount
-                         singular paramsAsSingleObject
-                         (contentType == CTTextCSV)
-                         (contentType == CTOctetStream) bField
-              let (tableTotal, queryTotal, body) =
-                    fromMaybe (Just 0, 0, "[]") row
-                  (status, contentRange) = rangeHeader queryTotal tableTotal
-              if singular && queryTotal /= 1
-                then do
-                  HT.condemn
-                  return $ singularityError (toInteger queryTotal)
-                else return $ responseLBS status [toHeader contentType, contentRange] (toS body)
+  (tableTotal, queryTotal, _ , body, gucHeaders, gucStatus) <-
+    lift . SQL.statement mempty $
+      Statements.createReadStatement
+        (QueryBuilder.readRequestToQuery req)
+        (if iPreferCount == Just EstimatedCount then
+           -- LIMIT maxRows + 1 so we can determine below that maxRows was surpassed
+           QueryBuilder.limitedQuery countQuery ((+ 1) <$> configDbMaxRows)
+         else
+           countQuery
+        )
+        (iAcceptContentType == CTSingularJSON)
+        (shouldCount iPreferCount)
+        (iAcceptContentType == CTTextCSV)
+        bField
+        ctxPgVersion
+        configDbPreparedStatements
 
-        (ActionInspect, TargetRoot, Nothing) -> do
-          let host = configHost conf
-              port = toInteger $ configPort conf
-              proxy = pickProxy $ toS <$> configProxyUri conf
-              uri Nothing = ("http", host, port, "/")
-              uri (Just Proxy { proxyScheme = s, proxyHost = h, proxyPort = p, proxyPath = b }) = (s, h, p, b)
-              uri' = uri proxy
-              encodeApi ti sd = encodeOpenAPI (M.elems allProcs) (toTableInfo ti) uri' sd (dbPrimaryKeys dbStructure)
-          body <- encodeApi <$> H.query schema accessibleTables <*> H.query schema schemaDescription
-          return $ responseLBS status200 [toHeader CTOpenAPI] $ toS body
+  total <- readTotal ctxConfig ctxApiRequest tableTotal countQuery
+  response <- liftEither $ gucResponse <$> gucStatus <*> gucHeaders
 
-        _ -> return notFound
+  let
+    (status, contentRange) = RangeQuery.rangeStatusHeader iTopLevelRange queryTotal total
+    headers =
+      [ contentRange
+      , ( "Content-Location"
+        , "/"
+            <> toS (qiName identifier)
+            <> if BS8.null iCanonicalQS then mempty else "?" <> toS iCanonicalQS
+        )
+      ]
+      ++ contentTypeHeaders context
 
-    where
-      toTableInfo :: [Table] -> [(Table, [Column], [Text])]
-      toTableInfo = map (\t ->
-        let tSchema = tableSchema t
-            tTable = tableName t
-            cols = filter (filterCol tSchema tTable) $ dbColumns dbStructure
-            pkeys = map pkName $ filter (filterPk tSchema tTable) allPrKeys
-        in (t, cols, pkeys))
-      notFound = responseLBS status404 [] ""
-      filterPk sc table pk = sc == (tableSchema . pkTable) pk && table == (tableName . pkTable) pk
-      filterCol :: Schema -> TableName -> Column -> Bool
-      filterCol sc tb Column{colTable=Table{tableSchema=s, tableName=t}} = s==sc && t==tb
-      allPrKeys = dbPrimaryKeys dbStructure
-      allProcs = dbProcs dbStructure
-      allOrigins = ("Access-Control-Allow-Origin", "*") :: Header
-      shouldCount = iPreferCount apiRequest
-      schema = toS $ configSchema conf
-      topLevelRange = fromMaybe allRange $ M.lookup "limit" $ iRange apiRequest
-      rangeHeader queryTotal tableTotal =
-        let lower = rangeOffset topLevelRange
-            upper = lower + toInteger queryTotal - 1
-            contentRange = contentRangeH lower upper (toInteger <$> tableTotal)
-            status = rangeStatus lower upper (toInteger <$> tableTotal)
-        in (status, contentRange)
+  failNotSingular iAcceptContentType queryTotal . response status headers $
+    if headersOnly then mempty else toS body
 
-      readReq = readRequest (configMaxRows conf) (dbRelations dbStructure) allProcs apiRequest
-      fldNames = fieldNames <$> readReq
-      readDbRequest = DbRead <$> readReq
-      mutateDbRequest = DbMutate <$> (mutateRequest apiRequest =<< fldNames)
-      selectQuery = requestToQuery schema False <$> readDbRequest
-      mutateQuery = requestToQuery schema False <$> mutateDbRequest
-      countQuery = requestToCountQuery schema <$> readDbRequest
-      readSqlParts = (,) <$> selectQuery <*> countQuery
-      mutateSqlParts = (,) <$> selectQuery <*> mutateQuery
-
-responseContentTypeOrError :: [ContentType] -> Action -> Either Response ContentType
-responseContentTypeOrError accepts action = serves contentTypesForRequest accepts
+readTotal :: AppConfig -> ApiRequest -> Maybe Int64 -> SQL.Snippet -> DbHandler (Maybe Int64)
+readTotal AppConfig{..} ApiRequest{..} tableTotal countQuery =
+  case iPreferCount of
+    Just PlannedCount ->
+      explain
+    Just EstimatedCount ->
+      if tableTotal > (fromIntegral <$> configDbMaxRows) then
+        max tableTotal <$> explain
+      else
+        return tableTotal
+    _ ->
+      return tableTotal
   where
-    contentTypesForRequest =
-      case action of
-        ActionRead ->    [CTApplicationJSON, CTSingularJSON, CTTextCSV, CTOctetStream]
-        ActionCreate ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-        ActionUpdate ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-        ActionDelete ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV]
-        ActionInvoke ->  [CTApplicationJSON, CTSingularJSON, CTTextCSV, CTOctetStream]
-        ActionInspect -> [CTOpenAPI, CTApplicationJSON]
-        ActionInfo ->    [CTTextCSV]
-    serves sProduces cAccepts =
-      case mutuallyAgreeable sProduces cAccepts of
-        Nothing -> do
-          let failed = intercalate ", " $ map (toS . toMime) cAccepts
-          Left $ simpleError status415 [] $
-            "None of these Content-Types are available: " <> failed
-        Just ct -> Right ct
+    explain =
+      lift . SQL.statement mempty . Statements.createExplainStatement countQuery $
+        configDbPreparedStatements
 
-binaryField :: ContentType -> [FieldName] -> Either Response (Maybe FieldName)
-binaryField CTOctetStream fldNames =
-  if length fldNames == 1 && fieldName /= Just "*"
-    then Right fieldName
-    else Left binaryFieldError
+handleCreate :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleCreate identifier@QualifiedIdentifier{..} context@RequestContext{..} = do
+  let
+    ApiRequest{..} = ctxApiRequest
+    pkCols = tablePKCols ctxDbStructure qiSchema qiName
+
+  WriteQueryResult{..} <- writeQuery identifier True pkCols context
+
+  let
+    response = gucResponse resGucStatus resGucHeaders
+    headers =
+      catMaybes
+        [ if null resFields then
+            Nothing
+          else
+            Just
+              ( HTTP.hLocation
+              , "/"
+                  <> toS qiName
+                  <> HTTP.renderSimpleQuery True (splitKeyValue <$> resFields)
+              )
+        , Just . RangeQuery.contentRangeH 1 0 $
+            if shouldCount iPreferCount then Just resQueryTotal else Nothing
+        , if null pkCols && isNothing iOnConflict then
+            Nothing
+          else
+            (\x -> ("Preference-Applied", BS8.pack $ show x)) <$> iPreferResolution
+        ]
+
+  failNotSingular iAcceptContentType resQueryTotal $
+    if iPreferRepresentation == Full then
+      response HTTP.status201 (headers ++ contentTypeHeaders context) (toS resBody)
+    else
+      response HTTP.status201 headers mempty
+
+handleUpdate :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleUpdate identifier context@(RequestContext _ _ ApiRequest{..} _) = do
+  WriteQueryResult{..} <- writeQuery identifier False mempty context
+
+  let
+    response = gucResponse resGucStatus resGucHeaders
+    fullRepr = iPreferRepresentation == Full
+    updateIsNoOp = Set.null iColumns
+    status
+      | resQueryTotal == 0 && not updateIsNoOp = HTTP.status404
+      | fullRepr = HTTP.status200
+      | otherwise = HTTP.status204
+    contentRangeHeader =
+      RangeQuery.contentRangeH 0 (resQueryTotal - 1) $
+        if shouldCount iPreferCount then Just resQueryTotal else Nothing
+
+  failNotSingular iAcceptContentType resQueryTotal $
+    if fullRepr then
+      response status (contentTypeHeaders context ++ [contentRangeHeader]) (toS resBody)
+    else
+      response status [contentRangeHeader] mempty
+
+handleSingleUpsert :: QualifiedIdentifier -> RequestContext-> DbHandler Wai.Response
+handleSingleUpsert identifier context@(RequestContext _ _ ApiRequest{..} _) = do
+  when (iTopLevelRange /= RangeQuery.allRange) $
+    throwError Error.PutRangeNotAllowedError
+
+  WriteQueryResult{..} <- writeQuery identifier False mempty context
+
+  let response = gucResponse resGucStatus resGucHeaders
+
+  -- Makes sure the querystring pk matches the payload pk
+  -- e.g. PUT /items?id=eq.1 { "id" : 1, .. } is accepted,
+  -- PUT /items?id=eq.14 { "id" : 2, .. } is rejected.
+  -- If this condition is not satisfied then nothing is inserted,
+  -- check the WHERE for INSERT in QueryBuilder.hs to see how it's done
+  when (resQueryTotal /= 1) $ do
+    lift SQL.condemn
+    throwError Error.PutMatchingPkError
+
+  return $
+    if iPreferRepresentation == Full then
+      response HTTP.status200 (contentTypeHeaders context) (toS resBody)
+    else
+      response HTTP.status204 (contentTypeHeaders context) mempty
+
+handleDelete :: QualifiedIdentifier -> RequestContext -> DbHandler Wai.Response
+handleDelete identifier context@(RequestContext _ _ ApiRequest{..} _) = do
+  WriteQueryResult{..} <- writeQuery identifier False mempty context
+
+  let
+    response = gucResponse resGucStatus resGucHeaders
+    contentRangeHeader =
+      RangeQuery.contentRangeH 1 0 $
+        if shouldCount iPreferCount then Just resQueryTotal else Nothing
+
+  failNotSingular iAcceptContentType resQueryTotal $
+    if iPreferRepresentation == Full then
+      response HTTP.status200
+        (contentTypeHeaders context ++ [contentRangeHeader])
+        (toS resBody)
+    else
+      response HTTP.status204 [contentRangeHeader] mempty
+
+handleInfo :: Monad m => QualifiedIdentifier -> RequestContext -> Handler m Wai.Response
+handleInfo identifier RequestContext{..} =
+  case find tableMatches $ dbTables ctxDbStructure of
+    Just table ->
+      return $ Wai.responseLBS HTTP.status200 [allOrigins, allowH table] mempty
+    Nothing ->
+      throwError Error.NotFound
   where
-    fieldName = headMay fldNames
-binaryField _ _ = Right Nothing
+    allOrigins = ("Access-Control-Allow-Origin", "*")
+    allowH table =
+      ( HTTP.hAllow
+      , BS8.intercalate "," $
+          ["OPTIONS,GET,HEAD"]
+          ++ ["POST" | tableInsertable table]
+          ++ ["PUT" | tableInsertable table && tableUpdatable table && hasPK]
+          ++ ["PATCH" | tableUpdatable table]
+          ++ ["DELETE" | tableDeletable table]
+      )
+    tableMatches table =
+      tableName table == qiName identifier
+      && tableSchema table == qiSchema identifier
+    hasPK =
+      not $ null $ tablePKCols ctxDbStructure (qiSchema identifier) (qiName identifier)
 
-splitKeyValue :: BS.ByteString -> (BS.ByteString, BS.ByteString)
-splitKeyValue kv = (k, BS.tail v)
-  where (k, v) = BS.break (== '=') kv
+handleInvoke :: InvokeMethod -> ProcDescription -> RequestContext -> DbHandler Wai.Response
+handleInvoke invMethod proc context@RequestContext{..} = do
+  let
+    ApiRequest{..} = ctxApiRequest
 
-renderLocationFields :: [BS.ByteString] -> BS.ByteString
-renderLocationFields fields =
-  renderSimpleQuery True $ map splitKeyValue fields
+    identifier =
+      QualifiedIdentifier
+        (pdSchema proc)
+        (fromMaybe (pdName proc) $ Proc.procTableName proc)
 
-rangeStatus :: Integer -> Integer -> Maybe Integer -> Status
-rangeStatus _ _ Nothing = status200
-rangeStatus lower upper (Just total)
-  | lower > total            = status416
-  | (1 + upper - lower) < total = status206
-  | otherwise               = status200
+    returnsSingle (ApiRequest.TargetProc target _) = Proc.procReturnsSingle target
+    returnsSingle _                                = False
 
-contentRangeH :: Integer -> Integer -> Maybe Integer -> Header
-contentRangeH lower upper total =
-    ("Content-Range", headerValue)
-    where
-      headerValue   = rangeString <> "/" <> totalString
-      rangeString
-        | totalNotZero && fromInRange = show lower <> "-" <> show upper
-        | otherwise = "*"
-      totalString   = fromMaybe "*" (show <$> total)
-      totalNotZero  = fromMaybe True ((/=) 0 <$> total)
-      fromInRange   = lower <= upper
+  req <- readRequest identifier context
+  bField <- binaryField context req
 
-extractQueryResult :: Maybe ResultsWithCount -> ResultsWithCount
-extractQueryResult = fromMaybe (Nothing, 0, [], "")
+  (tableTotal, queryTotal, body, gucHeaders, gucStatus) <-
+    lift . SQL.statement mempty $
+      Statements.callProcStatement
+        (returnsScalar iTarget)
+        (returnsSingle iTarget)
+        (QueryBuilder.requestToCallProcQuery
+          (QualifiedIdentifier (pdSchema proc) (pdName proc))
+          (Proc.specifiedProcArgs iColumns proc)
+          iPayload
+          (returnsScalar iTarget)
+          iPreferParameters
+          (ReqBuilder.returningCols req [])
+        )
+        (QueryBuilder.readRequestToQuery req)
+        (QueryBuilder.readRequestToCountQuery req)
+        (shouldCount iPreferCount)
+        (iAcceptContentType == CTSingularJSON)
+        (iAcceptContentType == CTTextCSV)
+        (iPreferParameters == Just MultipleObjects)
+        bField
+        ctxPgVersion
+        (configDbPreparedStatements ctxConfig)
+
+  response <- liftEither $ gucResponse <$> gucStatus <*> gucHeaders
+
+  let
+    (status, contentRange) =
+      RangeQuery.rangeStatusHeader iTopLevelRange queryTotal tableTotal
+
+  failNotSingular iAcceptContentType queryTotal $
+    response status
+      (contentTypeHeaders context ++ [contentRange])
+      (if invMethod == InvHead then mempty else toS body)
+
+handleOpenApi :: Bool -> Schema -> RequestContext -> DbHandler Wai.Response
+handleOpenApi headersOnly tSchema (RequestContext conf@AppConfig{..} dbStructure apiRequest _) = do
+  body <-
+    lift $ case configOpenApiMode of
+      OAFollowPriv ->
+        OpenAPI.encode conf dbStructure
+           <$> SQL.statement tSchema (DbStructure.accessibleTables configDbPreparedStatements)
+           <*> SQL.statement tSchema (DbStructure.accessibleProcs configDbPreparedStatements)
+           <*> SQL.statement tSchema (DbStructure.schemaDescription configDbPreparedStatements)
+      OAIgnorePriv ->
+        OpenAPI.encode conf dbStructure
+              (filter (\x -> tableSchema x == tSchema) $ DbStructure.dbTables dbStructure)
+              (Map.filterWithKey (\(QualifiedIdentifier sch _) _ ->  sch == tSchema) $ DbStructure.dbProcs dbStructure)
+          <$> SQL.statement tSchema (DbStructure.schemaDescription configDbPreparedStatements)
+      OADisabled ->
+        pure mempty
+
+  return $
+    Wai.responseLBS HTTP.status200
+      (ContentType.toHeader CTOpenAPI : maybeToList (profileHeader apiRequest))
+      (if headersOnly then mempty else toS body)
+
+txMode :: ApiRequest -> SQL.Mode
+txMode ApiRequest{..} =
+  case (iAction, iTarget) of
+    (ActionRead _, _) ->
+      SQL.Read
+    (ActionInfo, _) ->
+      SQL.Read
+    (ActionInspect _, _) ->
+      SQL.Read
+    (ActionInvoke InvGet, _) ->
+      SQL.Read
+    (ActionInvoke InvHead, _) ->
+      SQL.Read
+    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Stable} _) ->
+      SQL.Read
+    (ActionInvoke InvPost, TargetProc ProcDescription{pdVolatility=Immutable} _) ->
+      SQL.Read
+    _ ->
+      SQL.Write
+
+-- | Result from executing a write query on the database
+data WriteQueryResult = WriteQueryResult
+  { resQueryTotal :: Int64
+  , resFields     :: [ByteString]
+  , resBody       :: ByteString
+  , resGucStatus  :: Maybe HTTP.Status
+  , resGucHeaders :: [GucHeader]
+  }
+
+writeQuery :: QualifiedIdentifier -> Bool -> [Text] -> RequestContext -> DbHandler WriteQueryResult
+writeQuery identifier@QualifiedIdentifier{..} isInsert pkCols context@RequestContext{..} = do
+  readReq <- readRequest identifier context
+
+  mutateReq <-
+    liftEither $
+      ReqBuilder.mutateRequest qiSchema qiName ctxApiRequest
+        (tablePKCols ctxDbStructure qiSchema qiName)
+        readReq
+
+  (_, queryTotal, fields, body, gucHeaders, gucStatus) <-
+    lift . SQL.statement mempty $
+      Statements.createWriteStatement
+        (QueryBuilder.readRequestToQuery readReq)
+        (QueryBuilder.mutateRequestToQuery mutateReq)
+        (iAcceptContentType ctxApiRequest == CTSingularJSON)
+        isInsert
+        (iAcceptContentType ctxApiRequest == CTTextCSV)
+        (iPreferRepresentation ctxApiRequest)
+        pkCols
+        ctxPgVersion
+        (configDbPreparedStatements ctxConfig)
+
+  liftEither $ WriteQueryResult queryTotal fields body <$> gucStatus <*> gucHeaders
+
+-- | Response with headers and status overridden from GUCs.
+gucResponse
+  :: Maybe HTTP.Status
+  -> [GucHeader]
+  -> HTTP.Status
+  -> [HTTP.Header]
+  -> LBS.ByteString
+  -> Wai.Response
+gucResponse gucStatus gucHeaders status headers =
+  Wai.responseLBS (fromMaybe status gucStatus) $
+    addHeadersIfNotIncluded headers (map unwrapGucHeader gucHeaders)
+
+-- |
+-- Fail a response if a single JSON object was requested and not exactly one
+-- was found.
+failNotSingular :: ContentType -> Int64 -> Wai.Response -> DbHandler Wai.Response
+failNotSingular contentType queryTotal response =
+  if contentType == CTSingularJSON && queryTotal /= 1 then
+    do
+      lift SQL.condemn
+      throwError $ Error.singularityError queryTotal
+  else
+    return response
+
+shouldCount :: Maybe PreferCount -> Bool
+shouldCount preferCount =
+  preferCount == Just ExactCount || preferCount == Just EstimatedCount
+
+returnsScalar :: ApiRequest.Target -> Bool
+returnsScalar (TargetProc proc _) = Proc.procReturnsScalar proc
+returnsScalar _                   = False
+
+readRequest :: Monad m => QualifiedIdentifier -> RequestContext -> Handler m ReadRequest
+readRequest QualifiedIdentifier{..} (RequestContext AppConfig{..} dbStructure apiRequest _) =
+  liftEither $
+    ReqBuilder.readRequest qiSchema qiName configDbMaxRows
+      (dbRelationships dbStructure)
+      apiRequest
+
+contentTypeHeaders :: RequestContext -> [HTTP.Header]
+contentTypeHeaders RequestContext{..} =
+  ContentType.toHeader (iAcceptContentType ctxApiRequest) : maybeToList (profileHeader ctxApiRequest)
+
+-- | If raw(binary) output is requested, check that ContentType is one of the
+-- admitted rawContentTypes and that`?select=...` contains only one field other
+-- than `*`
+binaryField :: Monad m => RequestContext -> ReadRequest -> Handler m (Maybe FieldName)
+binaryField RequestContext{..} readReq
+  | returnsScalar (iTarget ctxApiRequest) && iAcceptContentType ctxApiRequest `elem` rawContentTypes ctxConfig =
+      return $ Just "pgrst_scalar"
+  | iAcceptContentType ctxApiRequest `elem` rawContentTypes ctxConfig =
+      let
+        fldNames = fstFieldNames readReq
+        fieldName = headMay fldNames
+      in
+      if length fldNames == 1 && fieldName /= Just "*" then
+        return fieldName
+      else
+        throwError $ Error.BinaryFieldError (iAcceptContentType ctxApiRequest)
+  | otherwise =
+      return Nothing
+
+rawContentTypes :: AppConfig -> [ContentType]
+rawContentTypes AppConfig{..} =
+  (ContentType.decodeContentType <$> configRawMediaTypes) `union` [CTOctetStream, CTTextPlain]
+
+profileHeader :: ApiRequest -> Maybe HTTP.Header
+profileHeader ApiRequest{..} =
+  (,) "Content-Profile" <$> (toS <$> iProfile)
+
+splitKeyValue :: ByteString -> (ByteString, ByteString)
+splitKeyValue kv =
+  (k, BS8.tail v)
+  where
+    (k, v) = BS8.break (== '=') kv

src/PostgREST/AppState.hs

@@ -0,0 +1,145 @@
+{-# LANGUAGE RecordWildCards #-}
+
+module PostgREST.AppState
+  ( AppState
+  , getConfig
+  , getDbStructure
+  , getIsWorkerOn
+  , getJsonDbS
+  , getMainThreadId
+  , getPgVersion
+  , getPool
+  , getTime
+  , init
+  , initWithPool
+  , logWithZTime
+  , putConfig
+  , putDbStructure
+  , putIsWorkerOn
+  , putJsonDbS
+  , putPgVersion
+  , releasePool
+  , signalListener
+  , waitListener
+  ) where
+
+import qualified Hasql.Pool as P
+
+import Control.AutoUpdate (defaultUpdateSettings, mkAutoUpdate,
+                           updateAction)
+import Data.IORef         (IORef, atomicWriteIORef, newIORef,
+                           readIORef)
+import Data.Time          (ZonedTime, defaultTimeLocale, formatTime,
+                           getZonedTime)
+import Data.Time.Clock    (UTCTime, getCurrentTime)
+
+import PostgREST.Config           (AppConfig (..))
+import PostgREST.Config.PgVersion (PgVersion (..), minimumPgVersion)
+import PostgREST.DbStructure      (DbStructure)
+
+import Protolude      hiding (toS)
+import Protolude.Conv (toS)
+
+
+data AppState = AppState
+  { statePool         :: P.Pool -- | Connection pool, either a 'Connection' or a 'ConnectionError'
+  , statePgVersion    :: IORef PgVersion
+  -- | No schema cache at the start. Will be filled in by the connectionWorker
+  , stateDbStructure  :: IORef (Maybe DbStructure)
+  -- | Cached DbStructure in json
+  , stateJsonDbS      :: IORef ByteString
+  -- | Helper ref to make sure just one connectionWorker can run at a time
+  , stateIsWorkerOn   :: IORef Bool
+  -- | Binary semaphore used to sync the listener(NOTIFY reload) with the connectionWorker.
+  , stateListener     :: MVar ()
+  -- | Config that can change at runtime
+  , stateConf         :: IORef AppConfig
+  -- | Time used for verifying JWT expiration
+  , stateGetTime      :: IO UTCTime
+  -- | Time with time zone used for worker logs
+  , stateGetZTime     :: IO ZonedTime
+  -- | Used for killing the main thread in case a subthread fails
+  , stateMainThreadId :: ThreadId
+  }
+
+init :: AppConfig -> IO AppState
+init conf = do
+  newPool <- initPool conf
+  initWithPool newPool conf
+
+initWithPool :: P.Pool -> AppConfig -> IO AppState
+initWithPool newPool conf =
+  AppState newPool
+    <$> newIORef minimumPgVersion -- assume we're in a supported version when starting, this will be corrected on a later step
+    <*> newIORef Nothing
+    <*> newIORef mempty
+    <*> newIORef False
+    <*> newEmptyMVar
+    <*> newIORef conf
+    <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime }
+    <*> mkAutoUpdate defaultUpdateSettings { updateAction = getZonedTime }
+    <*> myThreadId
+
+initPool :: AppConfig -> IO P.Pool
+initPool AppConfig{..} =
+  P.acquire (configDbPoolSize, configDbPoolTimeout, toS configDbUri)
+
+getPool :: AppState -> P.Pool
+getPool = statePool
+
+releasePool :: AppState -> IO ()
+releasePool AppState{..} = P.release statePool >> throwTo stateMainThreadId UserInterrupt
+
+getPgVersion :: AppState -> IO PgVersion
+getPgVersion = readIORef . statePgVersion
+
+putPgVersion :: AppState -> PgVersion -> IO ()
+putPgVersion = atomicWriteIORef . statePgVersion
+
+getDbStructure :: AppState -> IO (Maybe DbStructure)
+getDbStructure = readIORef . stateDbStructure
+
+putDbStructure :: AppState -> DbStructure -> IO ()
+putDbStructure appState structure =
+  atomicWriteIORef (stateDbStructure appState) $ Just structure
+
+getJsonDbS :: AppState -> IO ByteString
+getJsonDbS = readIORef . stateJsonDbS
+
+putJsonDbS :: AppState -> ByteString -> IO ()
+putJsonDbS appState = atomicWriteIORef (stateJsonDbS appState)
+
+getIsWorkerOn :: AppState -> IO Bool
+getIsWorkerOn = readIORef . stateIsWorkerOn
+
+putIsWorkerOn :: AppState -> Bool -> IO ()
+putIsWorkerOn = atomicWriteIORef . stateIsWorkerOn
+
+getConfig :: AppState -> IO AppConfig
+getConfig = readIORef . stateConf
+
+putConfig :: AppState -> AppConfig -> IO ()
+putConfig = atomicWriteIORef . stateConf
+
+getTime :: AppState -> IO UTCTime
+getTime = stateGetTime
+
+-- | Log to stderr with local time
+logWithZTime :: AppState -> Text -> IO ()
+logWithZTime appState txt = do
+  zTime <- stateGetZTime appState
+  hPutStrLn stderr $ toS (formatTime defaultTimeLocale "%d/%b/%Y:%T %z: " zTime) <> txt
+
+getMainThreadId :: AppState -> ThreadId
+getMainThreadId = stateMainThreadId
+
+-- | As this IO action uses `takeMVar` internally, it will only return once
+-- `stateListener` has been set using `signalListener`. This is currently used
+-- to syncronize workers.
+waitListener :: AppState -> IO ()
+waitListener = takeMVar . stateListener
+
+-- tryPutMVar doesn't lock the thread. It should always succeed since
+-- the connectionWorker is the only mvar producer.
+signalListener :: AppState -> IO ()
+signalListener appState = void $ tryPutMVar (stateListener appState) ()

src/PostgREST/Auth.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE FlexibleContexts #-}
 {-|
 Module      : PostgREST.Auth
 Description : PostgREST authorization functions.
@@ -11,82 +10,73 @@ Authentication should always be implemented in an external service.
 In the test suite there is an example of simple login function that can be used for a
 very simple authentication system inside the PostgreSQL database.
 -}
-module PostgREST.Auth (
-    containsRole
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.Auth
+  ( containsRole
   , jwtClaims
-  , JWTAttempt(..)
-  , parseJWK
+  , JWTClaims
   ) where
 
-import           Protolude        hiding ((&))
-import           Control.Lens
-import           Data.Aeson              (Value (..), decode, toJSON)
-import qualified Data.ByteString.Lazy    as BL
-import qualified Data.HashMap.Strict     as M
+import qualified Crypto.JWT          as JWT
+import qualified Data.Aeson          as JSON
+import qualified Data.HashMap.Strict as M
+import qualified Data.Vector         as V
 
-import           Crypto.JOSE.Compact
-import           Crypto.JOSE.JWK
-import           Crypto.JOSE.JWS
-import           Crypto.JOSE.Types
-import           Crypto.JWT
+import Control.Lens            (set)
+import Control.Monad.Except    (liftEither)
+import Data.Either.Combinators (mapLeft)
+import Data.Time.Clock         (UTCTime)
 
-{-|
-  Possible situations encountered with client JWTs
--}
-data JWTAttempt = JWTInvalid JWTError
-                | JWTMissingSecret
-                | JWTClaims (M.HashMap Text Value)
-                deriving (Eq, Show)
+import PostgREST.Config (AppConfig (..), JSPath, JSPathExp (..))
+import PostgREST.Error  (Error (..))
 
-{-|
-  Receives the JWT secret (from config) and a JWT and returns a map
-  of JWT claims.
--}
-jwtClaims :: Maybe JWK -> BL.ByteString -> IO JWTAttempt
-jwtClaims _ "" = return $ JWTClaims M.empty
-jwtClaims secret payload =
-  case secret of
-    Nothing -> return JWTMissingSecret
-    Just jwk -> do
-      let validation = defaultJWTValidationSettings
-      eJwt <- runExceptT $ do
-        jwt <- decodeCompact payload
-        validateJWSJWT validation jwk jwt
-        return jwt
-      return $ case eJwt of
-        Left e -> JWTInvalid e
-        Right jwt -> JWTClaims . claims2map . jwtClaimsSet $ jwt
+import Protolude
 
-{-|
-  Whether a response from jwtClaims contains a role claim
--}
-containsRole :: JWTAttempt -> Bool
-containsRole (JWTClaims claims) = M.member "role" claims
-containsRole _ = False
 
-{-|
-  Internal helper used to turn JWT ClaimSet into something
-  easier to work with
--}
-claims2map :: ClaimsSet -> M.HashMap Text Value
-claims2map = val2map . toJSON
- where
-  val2map (Object o) = o
-  val2map _ = M.empty
+type JWTClaims = M.HashMap Text JSON.Value
 
-parseJWK :: ByteString -> JWK
-parseJWK str =
-  fromMaybe (hs256jwk str) (decode (toS str) :: Maybe JWK)
+-- | Receives the JWT secret and audience (from config) and a JWT and returns a
+-- map of JWT claims.
+jwtClaims :: Monad m =>
+  AppConfig -> LByteString -> UTCTime -> ExceptT Error m JWTClaims
+jwtClaims _ "" _ = return M.empty
+jwtClaims AppConfig{..} payload time = do
+  secret <- liftEither . maybeToRight JwtTokenMissing $ configJWKS
+  eitherClaims <-
+    lift . runExceptT $
+      JWT.verifyClaimsAt validation secret time =<< JWT.decodeCompact payload
+  liftEither . mapLeft jwtClaimsError $ claimsMap configJwtRoleClaimKey <$> eitherClaims
+  where
+    validation =
+      JWT.defaultJWTValidationSettings audienceCheck & set JWT.allowedSkew 1
 
-{-|
-  Internal helper to generate HMAC-SHA256. When the jwt key in the
-  config file is a simple string rather than a JWK object, we'll
-  apply this function to it.
--}
-hs256jwk :: ByteString -> JWK
-hs256jwk key =
-  fromKeyMaterial km
-    & jwkUse .~ Just Sig
-    & jwkAlg .~ (Just $ JWSAlg HS256)
- where
-  km = OctKeyMaterial (OctKeyParameters Oct (Base64Octets key))
+    audienceCheck :: JWT.StringOrURI -> Bool
+    audienceCheck = maybe (const True) (==) configJwtAudience
+
+    jwtClaimsError :: JWT.JWTError -> Error
+    jwtClaimsError JWT.JWTExpired = JwtTokenInvalid "JWT expired"
+    jwtClaimsError e              = JwtTokenInvalid $ show e
+
+-- | Turn JWT ClaimSet into something easier to work with.
+--
+-- Also, here the jspath is applied to put the "role" in the map.
+claimsMap :: JSPath -> JWT.ClaimsSet -> JWTClaims
+claimsMap jspath claims =
+  case JSON.toJSON claims of
+    val@(JSON.Object o) ->
+      M.delete "role" o `M.union` role val
+    _ ->
+      M.empty
+  where
+    role value =
+      maybe M.empty (M.singleton "role") $ walkJSPath (Just value) jspath
+
+    walkJSPath :: Maybe JSON.Value -> JSPath -> Maybe JSON.Value
+    walkJSPath x                      []                = x
+    walkJSPath (Just (JSON.Object o)) (JSPKey key:rest) = walkJSPath (M.lookup key o) rest
+    walkJSPath (Just (JSON.Array ar)) (JSPIdx idx:rest) = walkJSPath (ar V.!? idx) rest
+    walkJSPath _                      _                 = Nothing
+
+-- | Whether a response from jwtClaims contains a role claim
+containsRole :: JWTClaims -> Bool
+containsRole = M.member "role"

src/PostgREST/CLI.hs

@@ -0,0 +1,217 @@
+{-# LANGUAGE NamedFieldPuns  #-}
+{-# LANGUAGE QuasiQuotes     #-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.CLI
+  ( main
+  , CLI (..)
+  , Command (..)
+  , readCLIShowHelp
+  ) where
+
+import qualified Data.Aeson                 as Aeson
+import qualified Data.ByteString.Lazy       as LBS
+import qualified Hasql.Pool                 as P
+import qualified Hasql.Transaction.Sessions as HT
+import qualified Options.Applicative        as O
+import qualified Protolude.Conv             as Conv
+
+import Data.Text.IO (hPutStrLn)
+import Text.Heredoc (str)
+
+import PostgREST.AppState    (AppState)
+import PostgREST.Config      (AppConfig (..))
+import PostgREST.DbStructure (queryDbStructure)
+import PostgREST.Version     (prettyVersion)
+import PostgREST.Workers     (reReadConfig)
+
+import qualified PostgREST.App      as App
+import qualified PostgREST.AppState as AppState
+import qualified PostgREST.Config   as Config
+
+import Protolude hiding (hPutStrLn)
+
+
+main :: App.SignalHandlerInstaller -> Maybe App.SocketRunner -> CLI -> IO ()
+main installSignalHandlers runAppWithSocket CLI{cliCommand, cliPath} = do
+  conf@AppConfig{..} <-
+    either panic identity <$> Config.readAppConfig mempty cliPath Nothing
+  appState <- AppState.init conf
+
+  -- Override the config with config options from the db
+  -- TODO: the same operation is repeated on connectionWorker, ideally this
+  -- would be done only once, but dump CmdDumpConfig needs it for tests.
+  when configDbConfig $ reReadConfig True appState
+
+  exec cliCommand appState
+  where
+    exec :: Command -> AppState -> IO ()
+    exec CmdDumpConfig appState = putStr . Config.toText =<< AppState.getConfig appState
+    exec CmdDumpSchema appState = putStrLn =<< dumpSchema appState
+    exec CmdRun appState = App.run installSignalHandlers runAppWithSocket appState
+
+-- | Dump DbStructure schema to JSON
+dumpSchema :: AppState -> IO LBS.ByteString
+dumpSchema appState = do
+  AppConfig{..} <- AppState.getConfig appState
+  result <-
+    let transaction = if configDbPreparedStatements then HT.transaction else HT.unpreparedTransaction in
+    P.use (AppState.getPool appState) $
+      transaction HT.ReadCommitted HT.Read $
+        queryDbStructure
+          (toList configDbSchemas)
+          configDbExtraSearchPath
+          configDbPreparedStatements
+  P.release $ AppState.getPool appState
+  case result of
+    Left e -> do
+      hPutStrLn stderr $ "An error ocurred when loading the schema cache:\n" <> show e
+      exitFailure
+    Right dbStructure -> return $ Aeson.encode dbStructure
+
+-- | Command line interface options
+data CLI = CLI
+  { cliCommand :: Command
+  , cliPath    :: Maybe FilePath
+  }
+
+data Command
+  = CmdRun
+  | CmdDumpConfig
+  | CmdDumpSchema
+
+-- | Read command line interface options. Also prints help.
+readCLIShowHelp :: Bool -> IO CLI
+readCLIShowHelp hasEnvironment =
+  O.customExecParser prefs opts
+  where
+    prefs = O.prefs $ O.showHelpOnError <> O.showHelpOnEmpty
+    opts = O.info parser $ O.fullDesc <> progDesc <> footer
+    parser = O.helper <*> exampleParser <*> cliParser
+
+    progDesc =
+      O.progDesc $
+        "PostgREST "
+        <> Conv.toS prettyVersion
+        <> " / create a REST API to an existing Postgres database"
+
+    footer =
+      O.footer $
+        "To run PostgREST, please pass the FILENAME argument"
+        <> " or set PGRST_ environment variables."
+
+    exampleParser =
+      O.infoOption exampleConfigFile $
+        O.long "example"
+        <> O.short 'e'
+        <> O.help "Show an example configuration file"
+
+    cliParser :: O.Parser CLI
+    cliParser =
+      CLI
+        <$> (dumpConfigFlag <|> dumpSchemaFlag)
+        <*> optionalIf hasEnvironment configFileOption
+
+    configFileOption =
+      O.strArgument $
+        O.metavar "FILENAME"
+        <> O.help "Path to configuration file (optional with PGRST_ environment variables)"
+
+    dumpConfigFlag =
+      O.flag CmdRun CmdDumpConfig $
+        O.long "dump-config"
+        <> O.help "Dump loaded configuration and exit"
+
+    dumpSchemaFlag =
+      O.flag CmdRun CmdDumpSchema $
+        O.long "dump-schema"
+        <> O.help "Dump loaded schema as JSON and exit (for debugging, output structure is unstable)"
+
+    optionalIf :: Alternative f => Bool -> f a -> f (Maybe a)
+    optionalIf True  = O.optional
+    optionalIf False = fmap Just
+
+exampleConfigFile :: [Char]
+exampleConfigFile =
+  [str|### REQUIRED:
+      |db-uri = "postgres://user:pass@localhost:5432/dbname"
+      |db-schema = "public"
+      |db-anon-role = "postgres"
+      |
+      |### OPTIONAL:
+      |## number of open connections in the pool
+      |db-pool = 10
+      |
+      |## Time to live, in seconds, for an idle database pool connection.
+      |db-pool-timeout = 10
+      |
+      |## extra schemas to add to the search_path of every request
+      |db-extra-search-path = "public"
+      |
+      |## limit rows in response
+      |# db-max-rows = 1000
+      |
+      |## stored proc to exec immediately after auth
+      |# db-pre-request = "stored_proc_name"
+      |
+      |## stored proc that overrides the root "/" spec
+      |## it must be inside the db-schema
+      |# db-root-spec = "stored_proc_name"
+      |
+      |## Notification channel for reloading the schema cache
+      |db-channel = "pgrst"
+      |
+      |## Enable or disable the notification channel
+      |db-channel-enabled = true
+      |
+      |## Enable in-database configuration
+      |db-config = true
+      |
+      |## how to terminate database transactions
+      |## possible values are:
+      |## commit (default)
+      |##   transaction is always committed, this can not be overriden
+      |## commit-allow-override
+      |##   transaction is committed, but can be overriden with Prefer tx=rollback header
+      |## rollback
+      |##   transaction is always rolled back, this can not be overriden
+      |## rollback-allow-override
+      |##   transaction is rolled back, but can be overriden with Prefer tx=commit header
+      |db-tx-end = "commit"
+      |
+      |## enable or disable prepared statements. disabling is only necessary when behind a connection pooler.
+      |## when disabled, statements will be parametrized but won't be prepared.
+      |db-prepared-statements = true
+      |
+      |server-host = "!4"
+      |server-port = 3000
+      |
+      |## unix socket location
+      |## if specified it takes precedence over server-port
+      |# server-unix-socket = "/tmp/pgrst.sock"
+      |
+      |## unix socket file mode
+      |## when none is provided, 660 is applied by default
+      |# server-unix-socket-mode = "660"
+      |
+      |## determine if the OpenAPI output should follow or ignore role privileges or be disabled entirely
+      |## admitted values: follow-privileges, ignore-privileges, disabled
+      |openapi-mode = "follow-privileges"
+      |
+      |## base url for the OpenAPI output
+      |openapi-server-proxy-uri = ""
+      |
+      |## choose a secret, JSON Web Key (or set) to enable JWT auth
+      |## (use "@filename" to load from separate file)
+      |# jwt-secret = "secret_with_at_least_32_characters"
+      |# jwt-aud = "your_audience_claim"
+      |jwt-secret-is-base64 = false
+      |
+      |## jspath to the role claim key
+      |jwt-role-claim-key = ".role"
+      |
+      |## content types to produce raw output
+      |# raw-media-types="image/png, image/jpg"
+      |
+      |## logging level, the admitted values are: crit, error, warn and info.
+      |log-level = "error"
+      |]

src/PostgREST/Config.hs

@@ -1,196 +1,446 @@
-{-# OPTIONS_GHC -fno-warn-type-defaults #-}
 {-|
 Module      : PostgREST.Config
-Description : Manages PostgREST configuration options.
+Description : Manages PostgREST configuration type and parser.
 
-This module provides a helper function to read the command line
-arguments using the optparse-applicative and the AppConfig type to store
-them.  It also can be used to define other middleware configuration that
-may be delegated to some sort of external configuration.
-
-It currently includes a hardcoded CORS policy but this could easly be
-turned in configurable behaviour if needed.
-
-Other hardcoded options such as the minimum version number also belong here.
 -}
-module PostgREST.Config ( prettyVersion
-                        , readOptions
-                        , corsPolicy
-                        , minimumPgVersion
-                        , PgVersion (..)
-                        , AppConfig (..)
-                        )
-       where
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE LambdaCase            #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE RecordWildCards       #-}
+{-# OPTIONS_GHC -fno-warn-type-defaults #-}
 
-import           System.IO.Error             (IOError)
-import           Control.Applicative
-import qualified Data.ByteString             as B
-import qualified Data.ByteString.Char8       as BS
-import qualified Data.CaseInsensitive        as CI
-import qualified Data.Configurator           as C
-import qualified Data.Configurator.Parser    as C
-import           Data.Configurator.Types     (Value(..))
-import           Data.List                   (lookup)
-import           Data.Monoid
-import           Data.Scientific             (floatingOrInteger)
-import           Data.Text                   (strip, intercalate, lines)
-import           Data.Text.Encoding          (encodeUtf8)
-import           Data.Text.IO                (hPutStrLn)
-import           Data.Version                (versionBranch)
-import           Network.Wai
-import           Network.Wai.Middleware.Cors (CorsResourcePolicy (..))
-import           Options.Applicative hiding  (str)
-import           Paths_postgrest             (version)
-import           System.IO                   (hPrint)
-import           Text.Heredoc
-import           Text.PrettyPrint.ANSI.Leijen hiding ((<>), (<$>))
-import qualified Text.PrettyPrint.ANSI.Leijen as L
-import           Protolude hiding            (intercalate, (<>), hPutStrLn)
+module PostgREST.Config
+  ( AppConfig (..)
+  , Environment
+  , JSPath
+  , JSPathExp(..)
+  , LogLevel(..)
+  , OpenAPIMode(..)
+  , Proxy(..)
+  , toText
+  , isMalformedProxyUri
+  , readAppConfig
+  , readPGRSTEnvironment
+  , toURI
+  , parseSecret
+  ) where
 
--- | Config file settings for the server
-data AppConfig = AppConfig {
-    configDatabase          :: Text
-  , configAnonRole          :: Text
-  , configProxyUri          :: Maybe Text
-  , configSchema            :: Text
-  , configHost              :: Text
-  , configPort              :: Int
+import qualified Crypto.JOSE.Types      as JOSE
+import qualified Crypto.JWT             as JWT
+import qualified Data.Aeson             as JSON
+import qualified Data.ByteString        as B
+import qualified Data.ByteString.Base64 as B64
+import qualified Data.ByteString.Char8  as BS
+import qualified Data.Configurator      as C
+import qualified Data.Map.Strict        as M
+import qualified Data.Text              as T
 
-  , configJwtSecret         :: Maybe B.ByteString
-  , configJwtSecretIsBase64 :: Bool
+import qualified GHC.Show (show)
 
-  , configPool              :: Int
-  , configMaxRows           :: Maybe Integer
-  , configReqCheck          :: Maybe Text
-  , configQuiet             :: Bool
+import Control.Lens            (preview)
+import Control.Monad           (fail)
+import Crypto.JWT              (JWK, JWKSet, StringOrURI, stringOrUri)
+import Data.Aeson              (encode, toJSON)
+import Data.Either.Combinators (mapLeft)
+import Data.List               (lookup)
+import Data.List.NonEmpty      (fromList, toList)
+import Data.Maybe              (fromJust)
+import Data.Scientific         (floatingOrInteger)
+import Data.Time.Clock         (NominalDiffTime)
+import Numeric                 (readOct, showOct)
+import System.Environment      (getEnvironment)
+import System.Posix.Types      (FileMode)
+
+import PostgREST.Config.JSPath           (JSPath, JSPathExp (..),
+                                          pRoleClaimKey)
+import PostgREST.Config.Proxy            (Proxy (..),
+                                          isMalformedProxyUri, toURI)
+import PostgREST.DbStructure.Identifiers (QualifiedIdentifier, toQi)
+
+import Protolude      hiding (Proxy, toList, toS)
+import Protolude.Conv (toS)
+
+
+data AppConfig = AppConfig
+  { configAppSettings           :: [(Text, Text)]
+  , configDbAnonRole            :: Text
+  , configDbChannel             :: Text
+  , configDbChannelEnabled      :: Bool
+  , configDbExtraSearchPath     :: [Text]
+  , configDbMaxRows             :: Maybe Integer
+  , configDbPoolSize            :: Int
+  , configDbPoolTimeout         :: NominalDiffTime
+  , configDbPreRequest          :: Maybe QualifiedIdentifier
+  , configDbPreparedStatements  :: Bool
+  , configDbRootSpec            :: Maybe QualifiedIdentifier
+  , configDbSchemas             :: NonEmpty Text
+  , configDbConfig              :: Bool
+  , configDbTxAllowOverride     :: Bool
+  , configDbTxRollbackAll       :: Bool
+  , configDbUri                 :: Text
+  , configFilePath              :: Maybe FilePath
+  , configJWKS                  :: Maybe JWKSet
+  , configJwtAudience           :: Maybe StringOrURI
+  , configJwtRoleClaimKey       :: JSPath
+  , configJwtSecret             :: Maybe B.ByteString
+  , configJwtSecretIsBase64     :: Bool
+  , configLogLevel              :: LogLevel
+  , configOpenApiMode           :: OpenAPIMode
+  , configOpenApiServerProxyUri :: Maybe Text
+  , configRawMediaTypes         :: [B.ByteString]
+  , configServerHost            :: Text
+  , configServerPort            :: Int
+  , configServerUnixSocket      :: Maybe FilePath
+  , configServerUnixSocketMode  :: FileMode
   }
 
-defaultCorsPolicy :: CorsResourcePolicy
-defaultCorsPolicy =  CorsResourcePolicy Nothing
-  ["GET", "POST", "PATCH", "DELETE", "OPTIONS"] ["Authorization"] Nothing
-  (Just $ 60*60*24) False False True
+data LogLevel = LogCrit | LogError | LogWarn | LogInfo
 
--- | CORS policy to be used in by Wai Cors middleware
-corsPolicy :: Request -> Maybe CorsResourcePolicy
-corsPolicy req = case lookup "origin" headers of
-  Just origin -> Just defaultCorsPolicy {
-      corsOrigins = Just ([origin], True)
-    , corsRequestHeaders = "Authentication":accHeaders
-    , corsExposedHeaders = Just [
-        "Content-Encoding", "Content-Location", "Content-Range", "Content-Type"
-      , "Date", "Location", "Server", "Transfer-Encoding", "Range-Unit"
-      ]
-    }
-  Nothing -> Nothing
+instance Show LogLevel where
+  show LogCrit  = "crit"
+  show LogError = "error"
+  show LogWarn  = "warn"
+  show LogInfo  = "info"
+
+data OpenAPIMode = OAFollowPriv | OAIgnorePriv | OADisabled
+  deriving Eq
+
+instance Show OpenAPIMode where
+  show OAFollowPriv = "follow-privileges"
+  show OAIgnorePriv = "ignore-privileges"
+  show OADisabled   = "disabled"
+
+-- | Dump the config
+toText :: AppConfig -> Text
+toText conf =
+  unlines $ (\(k, v) -> k <> " = " <> v) <$> pgrstSettings ++ appSettings
   where
-    headers = requestHeaders req
-    accHeaders = case lookup "access-control-request-headers" headers of
-      Just hdrs -> map (CI.mk . toS . strip . toS) $ BS.split ',' hdrs
-      Nothing -> []
+    -- apply conf to all pgrst settings
+    pgrstSettings = (\(k, v) -> (k, v conf)) <$>
+      [("db-anon-role",              q . configDbAnonRole)
+      ,("db-channel",                q . configDbChannel)
+      ,("db-channel-enabled",            T.toLower . show . configDbChannelEnabled)
+      ,("db-extra-search-path",      q . T.intercalate "," . configDbExtraSearchPath)
+      ,("db-max-rows",                   maybe "\"\"" show . configDbMaxRows)
+      ,("db-pool",                       show . configDbPoolSize)
+      ,("db-pool-timeout",               show . floor . configDbPoolTimeout)
+      ,("db-pre-request",            q . maybe mempty show . configDbPreRequest)
+      ,("db-prepared-statements",        T.toLower . show . configDbPreparedStatements)
+      ,("db-root-spec",              q . maybe mempty show . configDbRootSpec)
+      ,("db-schemas",                q . T.intercalate "," . toList . configDbSchemas)
+      ,("db-config",                 q . T.toLower . show . configDbConfig)
+      ,("db-tx-end",                 q . showTxEnd)
+      ,("db-uri",                    q . configDbUri)
+      ,("jwt-aud",                       toS . encode . maybe "" toJSON . configJwtAudience)
+      ,("jwt-role-claim-key",        q . T.intercalate mempty . fmap show . configJwtRoleClaimKey)
+      ,("jwt-secret",                q . toS . showJwtSecret)
+      ,("jwt-secret-is-base64",          T.toLower . show . configJwtSecretIsBase64)
+      ,("log-level",                 q . show . configLogLevel)
+      ,("openapi-mode",              q . show . configOpenApiMode)
+      ,("openapi-server-proxy-uri",  q . fromMaybe mempty . configOpenApiServerProxyUri)
+      ,("raw-media-types",           q . toS . B.intercalate "," . configRawMediaTypes)
+      ,("server-host",               q . configServerHost)
+      ,("server-port",                   show . configServerPort)
+      ,("server-unix-socket",        q . maybe mempty T.pack . configServerUnixSocket)
+      ,("server-unix-socket-mode",   q . T.pack . showSocketMode)
+      ]
 
--- | User friendly version number
-prettyVersion :: Text
-prettyVersion = intercalate "." $ map show $ versionBranch version
+    -- quote all app.settings
+    appSettings = second q <$> configAppSettings conf
 
--- | Function to read and parse options from the command line
-readOptions :: IO AppConfig
-readOptions = do
-  -- First read the config file path from command line
-  cfgPath <- customExecParser parserPrefs opts
-  -- Now read the actual config file
-  conf <- catch
-    (C.readConfig =<< C.load [C.Required cfgPath])
-    configNotfoundHint
+    -- quote strings and replace " with \"
+    q s = "\"" <> T.replace "\"" "\\\"" s <> "\""
 
-  let (mAppConf, errs) = flip C.runParserA conf $
-        AppConfig <$>
-            C.key "db-uri"
-          <*> C.key "db-anon-role"
-          <*> C.key "server-proxy-uri"
-          <*> C.key "db-schema"
-          <*> (fromMaybe "*4" . mfilter (/= "") <$> C.key "server-host")
-          <*> (fromMaybe 3000 . join . fmap coerceInt <$> C.key "server-port")
-          <*> (fmap encodeUtf8 . mfilter (/= "") <$> C.key "jwt-secret")
-          <*> (fromMaybe False . join . fmap coerceBool <$> C.key "secret-is-base64")
-          <*> (fromMaybe 10 . join . fmap coerceInt <$> C.key "db-pool")
-          <*> (join . fmap coerceInt <$> C.key "max-rows")
-          <*> (mfilter (/= "") <$> C.key "pre-request")
-          <*> pure False
+    showTxEnd c = case (configDbTxRollbackAll c, configDbTxAllowOverride c) of
+      ( False, False ) -> "commit"
+      ( False, True  ) -> "commit-allow-override"
+      ( True , False ) -> "rollback"
+      ( True , True  ) -> "rollback-allow-override"
+    showJwtSecret c
+      | configJwtSecretIsBase64 c = B64.encode secret
+      | otherwise                 = toS secret
+      where
+        secret = fromMaybe mempty $ configJwtSecret c
+    showSocketMode c = showOct (configServerUnixSocketMode c) mempty
 
-  case mAppConf of
-    Nothing -> do
-      forM_ errs $ hPrint stderr
-      exitFailure
-    Just appConf ->
-      return appConf
+-- This class is needed for the polymorphism of overrideFromDbOrEnvironment
+-- because C.required and C.optional have different signatures
+class JustIfMaybe a b where
+  justIfMaybe :: a -> b
 
- where
-  coerceInt :: (Read i, Integral i) => Value -> Maybe i
-  coerceInt (Number x) = rightToMaybe $ floatingOrInteger x
-  coerceInt (String x) = readMaybe $ toS x
-  coerceInt _ = Nothing
+instance JustIfMaybe a a where
+  justIfMaybe a = a
 
-  coerceBool ::  Value -> Maybe Bool
-  coerceBool (Bool b) = Just b
-  coerceBool (String x) = readMaybe $ toS x
-  coerceBool _ = Nothing
+instance JustIfMaybe a (Maybe a) where
+  justIfMaybe a = Just a
 
-  opts = info (helper <*> pathParser) $
-           fullDesc
-           <> progDesc (
-               "PostgREST "
-               <> toS prettyVersion
-               <> " / create a REST API to an existing Postgres database"
-             )
-           <> footerDoc (Just $
-               text "Example Config File:"
-               L.<> nest 2 (hardline L.<> exampleCfg)
-             )
+-- | Reads and parses the config and overrides its parameters from env vars,
+-- files or db settings.
+readAppConfig :: [(Text, Text)] -> Maybe FilePath -> Maybe Text -> IO (Either Text AppConfig)
+readAppConfig dbSettings optPath prevDbUri = do
+  env <- readPGRSTEnvironment
+  -- if no filename provided, start with an empty map to read config from environment
+  conf <- maybe (return $ Right M.empty) loadConfig optPath
 
-  parserPrefs = prefs showHelpOnError
+  case C.runParser (parser optPath env dbSettings) =<< mapLeft show conf of
+    Left err ->
+      return . Left $ "Error in config " <> err
+    Right parsedConfig ->
+      Right <$> decodeLoadFiles parsedConfig
+  where
+    -- Both C.ParseError and IOError are shown here
+    loadConfig :: FilePath -> IO (Either SomeException C.Config)
+    loadConfig = try . C.load
 
-  configNotfoundHint :: IOError -> IO a
-  configNotfoundHint e = do
-    hPutStrLn stderr $
-      "Cannot open config file:\n\t" <> show e
-    exitFailure
+    decodeLoadFiles :: AppConfig -> IO AppConfig
+    decodeLoadFiles parsedConfig =
+      decodeJWKS <$>
+        (decodeSecret =<< readSecretFile =<< readDbUriFile prevDbUri parsedConfig)
 
-  exampleCfg :: Doc
-  exampleCfg = vsep . map (text . toS) . lines $
-    [str|db-uri = "postgres://user:pass@localhost:5432/dbname"
-        |db-schema = "public"
-        |db-anon-role = "postgres"
-        |db-pool = 10
-        |
-        |server-host = "*4"
-        |server-port = 3000
-        |
-        |## base url for swagger output
-        |# server-proxy-uri = ""
-        |
-        |## choose a secret to enable JWT auth
-        |## (use "@filename" to load from separate file)
-        |# jwt-secret = "foo"
-        |# secret-is-base64 = false
-        |
-        |## limit rows in response
-        |# max-rows = 1000
-        |
-        |## stored proc to exec immediately after auth
-        |# pre-request = "stored_proc_name"
-        |]
+parser :: Maybe FilePath -> Environment -> [(Text, Text)] -> C.Parser C.Config AppConfig
+parser optPath env dbSettings =
+  AppConfig
+    <$> parseAppSettings "app.settings"
+    <*> reqString "db-anon-role"
+    <*> (fromMaybe "pgrst" <$> optString "db-channel")
+    <*> (fromMaybe True <$> optBool "db-channel-enabled")
+    <*> (maybe ["public"] splitOnCommas <$> optValue "db-extra-search-path")
+    <*> optWithAlias (optInt "db-max-rows")
+                     (optInt "max-rows")
+    <*> (fromMaybe 10 <$> optInt "db-pool")
+    <*> (fromIntegral . fromMaybe 10 <$> optInt "db-pool-timeout")
+    <*> (fmap toQi <$> optWithAlias (optString "db-pre-request")
+                                    (optString "pre-request"))
+    <*> (fromMaybe True <$> optBool "db-prepared-statements")
+    <*> (fmap toQi <$> optWithAlias (optString "db-root-spec")
+                                    (optString "root-spec"))
+    <*> (fromList . splitOnCommas <$> reqWithAlias (optValue "db-schemas")
+                                                   (optValue "db-schema")
+                                                   "missing key: either db-schemas or db-schema must be set")
+    <*> (fromMaybe True <$> optBool "db-config")
+    <*> parseTxEnd "db-tx-end" snd
+    <*> parseTxEnd "db-tx-end" fst
+    <*> reqString "db-uri"
+    <*> pure optPath
+    <*> pure Nothing
+    <*> parseJwtAudience "jwt-aud"
+    <*> parseRoleClaimKey "jwt-role-claim-key" "role-claim-key"
+    <*> (fmap encodeUtf8 <$> optString "jwt-secret")
+    <*> (fromMaybe False <$> optWithAlias
+          (optBool "jwt-secret-is-base64")
+          (optBool "secret-is-base64"))
+    <*> parseLogLevel "log-level"
+    <*> parseOpenAPIMode "openapi-mode"
+    <*> parseOpenAPIServerProxyURI "openapi-server-proxy-uri"
+    <*> (maybe [] (fmap encodeUtf8 . splitOnCommas) <$> optValue "raw-media-types")
+    <*> (fromMaybe "!4" <$> optString "server-host")
+    <*> (fromMaybe 3000 <$> optInt "server-port")
+    <*> (fmap T.unpack <$> optString "server-unix-socket")
+    <*> parseSocketFileMode "server-unix-socket-mode"
+  where
+    parseAppSettings :: C.Key -> C.Parser C.Config [(Text, Text)]
+    parseAppSettings key = addFromEnv . fmap (fmap coerceText) <$> C.subassocs key C.value
+      where
+        addFromEnv f = M.toList $ M.union fromEnv $ M.fromList f
+        fromEnv = M.mapKeys fromJust $ M.filterWithKey (\k _ -> isJust k) $ M.mapKeys normalize env
+        normalize k = ("app.settings." <>) <$> T.stripPrefix "PGRST_APP_SETTINGS_" (toS k)
 
-pathParser :: Parser FilePath
-pathParser =
-  strArgument $
-    metavar "FILENAME" <>
-    help "Path to configuration file"
+    parseSocketFileMode :: C.Key -> C.Parser C.Config FileMode
+    parseSocketFileMode k =
+      optString k >>= \case
+        Nothing -> pure 432 -- return default 660 mode if no value was provided
+        Just fileModeText ->
+          case readOct $ T.unpack fileModeText of
+            []              ->
+              fail "Invalid server-unix-socket-mode: not an octal"
+            (fileMode, _):_ ->
+              if fileMode < 384 || fileMode > 511
+                then fail "Invalid server-unix-socket-mode: needs to be between 600 and 777"
+                else pure fileMode
 
-data PgVersion = PgVersion {
-  pgvNum  :: Int32
-, pgvName :: Text
-}
+    parseOpenAPIMode :: C.Key -> C.Parser C.Config OpenAPIMode
+    parseOpenAPIMode k =
+      optString k >>= \case
+        Nothing                  -> pure OAFollowPriv
+        Just "follow-privileges" -> pure OAFollowPriv
+        Just "ignore-privileges" -> pure OAIgnorePriv
+        Just "disabled"          -> pure OADisabled
+        Just _                   -> fail "Invalid openapi-mode. Check your configuration."
 
--- | Tells the minimum PostgreSQL version required by this version of PostgREST
-minimumPgVersion :: PgVersion
-minimumPgVersion = PgVersion 90300 "9.3"
+    parseOpenAPIServerProxyURI :: C.Key -> C.Parser C.Config (Maybe Text)
+    parseOpenAPIServerProxyURI k =
+      optString k >>= \case
+        Nothing                            -> pure Nothing
+        Just val | isMalformedProxyUri val -> fail "Malformed proxy uri, a correct example: https://example.com:8443/basePath"
+                 | otherwise               -> pure $ Just val
+
+    parseJwtAudience :: C.Key -> C.Parser C.Config (Maybe StringOrURI)
+    parseJwtAudience k =
+      optString k >>= \case
+        Nothing -> pure Nothing -- no audience in config file
+        Just aud -> case preview stringOrUri (T.unpack aud) of
+          Nothing -> fail "Invalid Jwt audience. Check your configuration."
+          aud' -> pure aud'
+
+    parseLogLevel :: C.Key -> C.Parser C.Config LogLevel
+    parseLogLevel k =
+      optString k >>= \case
+        Nothing      -> pure LogError
+        Just "crit"  -> pure LogCrit
+        Just "error" -> pure LogError
+        Just "warn"  -> pure LogWarn
+        Just "info"  -> pure LogInfo
+        Just _       -> fail "Invalid logging level. Check your configuration."
+
+    parseTxEnd :: C.Key -> ((Bool, Bool) -> Bool) -> C.Parser C.Config Bool
+    parseTxEnd k f =
+      optString k >>= \case
+        --                                          RollbackAll AllowOverride
+        Nothing                        -> pure $ f (False,      False)
+        Just "commit"                  -> pure $ f (False,      False)
+        Just "commit-allow-override"   -> pure $ f (False,      True)
+        Just "rollback"                -> pure $ f (True,       False)
+        Just "rollback-allow-override" -> pure $ f (True,       True)
+        Just _                         -> fail "Invalid transaction termination. Check your configuration."
+
+    parseRoleClaimKey :: C.Key -> C.Key -> C.Parser C.Config JSPath
+    parseRoleClaimKey k al =
+      optWithAlias (optString k) (optString al) >>= \case
+        Nothing  -> pure [JSPKey "role"]
+        Just rck -> either (fail . show) pure $ pRoleClaimKey rck
+
+    reqWithAlias :: C.Parser C.Config (Maybe a) -> C.Parser C.Config (Maybe a) -> [Char] -> C.Parser C.Config a
+    reqWithAlias orig alias err =
+      orig >>= \case
+        Just v  -> pure v
+        Nothing ->
+          alias >>= \case
+            Just v  -> pure v
+            Nothing -> fail err
+
+    optWithAlias :: C.Parser C.Config (Maybe a) -> C.Parser C.Config (Maybe a) -> C.Parser C.Config (Maybe a)
+    optWithAlias orig alias =
+      orig >>= \case
+        Just v  -> pure $ Just v
+        Nothing -> alias
+
+    reqString :: C.Key -> C.Parser C.Config Text
+    reqString k = overrideFromDbOrEnvironment C.required k coerceText
+
+    optString :: C.Key -> C.Parser C.Config (Maybe Text)
+    optString k = mfilter (/= "") <$> overrideFromDbOrEnvironment C.optional k coerceText
+
+    optValue :: C.Key -> C.Parser C.Config (Maybe C.Value)
+    optValue k = overrideFromDbOrEnvironment C.optional k identity
+
+    optInt :: (Read i, Integral i) => C.Key -> C.Parser C.Config (Maybe i)
+    optInt k = join <$> overrideFromDbOrEnvironment C.optional k coerceInt
+
+    optBool :: C.Key -> C.Parser C.Config (Maybe Bool)
+    optBool k = join <$> overrideFromDbOrEnvironment C.optional k coerceBool
+
+    overrideFromDbOrEnvironment :: JustIfMaybe a b =>
+                               (C.Key -> C.Parser C.Value a -> C.Parser C.Config b) ->
+                               C.Key -> (C.Value -> a) -> C.Parser C.Config b
+    overrideFromDbOrEnvironment necessity key coercion =
+      case reloadableDbSetting <|> M.lookup envVarName env of
+        Just dbOrEnvVal -> pure $ justIfMaybe $ coercion $ C.String dbOrEnvVal
+        Nothing  -> necessity key (coercion <$> C.value)
+      where
+        dashToUnderscore '-' = '_'
+        dashToUnderscore c   = c
+        envVarName = "PGRST_" <> (toUpper . dashToUnderscore <$> toS key)
+        reloadableDbSetting =
+          let dbSettingName = T.pack $ dashToUnderscore <$> toS key in
+          if dbSettingName `notElem` [
+            "server_host", "server_port", "server_unix_socket", "server_unix_socket_mode", "log_level",
+            "db_anon_role", "db_uri", "db_channel_enabled", "db_channel", "db_pool", "db_pool_timeout", "db_config"]
+          then lookup dbSettingName dbSettings
+          else Nothing
+
+    coerceText :: C.Value -> Text
+    coerceText (C.String s) = s
+    coerceText v            = show v
+
+    coerceInt :: (Read i, Integral i) => C.Value -> Maybe i
+    coerceInt (C.Number x) = rightToMaybe $ floatingOrInteger x
+    coerceInt (C.String x) = readMaybe $ toS x
+    coerceInt _            = Nothing
+
+    coerceBool :: C.Value -> Maybe Bool
+    coerceBool (C.Bool b)   = Just b
+    coerceBool (C.String s) =
+      -- parse all kinds of text: True, true, TRUE, "true", ...
+      case readMaybe . toS $ T.toTitle $ T.filter isAlpha $ toS s of
+        Just b  -> Just b
+        -- numeric instead?
+        Nothing -> (> 0) <$> (readMaybe $ toS s :: Maybe Integer)
+    coerceBool _            = Nothing
+
+    splitOnCommas :: C.Value -> [Text]
+    splitOnCommas (C.String s) = T.strip <$> T.splitOn "," s
+    splitOnCommas _            = []
+
+-- | Read the JWT secret from a file if configJwtSecret is actually a
+-- filepath(has @ as its prefix). To check if the JWT secret is provided is
+-- in fact a file path, it must be decoded as 'Text' to be processed.
+readSecretFile :: AppConfig -> IO AppConfig
+readSecretFile conf =
+  maybe (return conf) readSecret maybeFilename
+  where
+    maybeFilename = T.stripPrefix "@" . decodeUtf8 =<< configJwtSecret conf
+    readSecret filename = do
+      jwtSecret <- chomp <$> BS.readFile (toS filename)
+      return $ conf { configJwtSecret = Just jwtSecret }
+    chomp bs = fromMaybe bs (BS.stripSuffix "\n" bs)
+
+decodeSecret :: AppConfig -> IO AppConfig
+decodeSecret conf@AppConfig{..} =
+  case (configJwtSecretIsBase64, configJwtSecret) of
+    (True, Just secret) ->
+      either fail (return . updateSecret) $ decodeB64 secret
+    _ -> return conf
+  where
+    updateSecret bs = conf { configJwtSecret = Just bs }
+    decodeB64 = B64.decode . encodeUtf8 . T.strip . replaceUrlChars . decodeUtf8
+    replaceUrlChars = T.replace "_" "/" . T.replace "-" "+" . T.replace "." "="
+
+-- | Parse `jwt-secret` configuration option and turn into a JWKSet.
+--
+-- There are three ways to specify `jwt-secret`: text secret, JSON Web Key
+-- (JWK), or JSON Web Key Set (JWKS). The first two are converted into a JWKSet
+-- with one key and the last is converted as is.
+decodeJWKS :: AppConfig -> AppConfig
+decodeJWKS conf =
+  conf { configJWKS = parseSecret <$> configJwtSecret conf }
+
+parseSecret :: ByteString -> JWKSet
+parseSecret bytes =
+  fromMaybe (maybe secret (\jwk' -> JWT.JWKSet [jwk']) maybeJWK)
+    maybeJWKSet
+  where
+    maybeJWKSet = JSON.decode (toS bytes) :: Maybe JWKSet
+    maybeJWK = JSON.decode (toS bytes) :: Maybe JWK
+    secret = JWT.JWKSet [JWT.fromKeyMaterial keyMaterial]
+    keyMaterial = JWT.OctKeyMaterial . JWT.OctKeyParameters $ JOSE.Base64Octets bytes
+
+-- | Read database uri from a separate file if `db-uri` is a filepath.
+readDbUriFile :: Maybe Text -> AppConfig -> IO AppConfig
+readDbUriFile maybeDbUri conf =
+  case maybeDbUri of
+    Just prevDbUri ->
+      pure $ conf { configDbUri = prevDbUri }
+    Nothing ->
+      case T.stripPrefix "@" $ configDbUri conf of
+        Nothing -> return conf
+        Just filename -> do
+          dbUri <- T.strip <$> readFile (toS filename)
+          return $ conf { configDbUri = dbUri }
+
+type Environment = M.Map [Char] Text
+
+-- | Read environment variables that start with PGRST_
+readPGRSTEnvironment :: IO Environment
+readPGRSTEnvironment =
+  M.map T.pack . M.fromList . filter (isPrefixOf "PGRST_" . fst) <$> getEnvironment

src/PostgREST/Config/Database.hs

@@ -0,0 +1,56 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module PostgREST.Config.Database
+  ( queryDbSettings
+  , queryPgVersion
+  ) where
+
+import PostgREST.Config.PgVersion (PgVersion (..))
+
+import qualified Hasql.Decoders             as HD
+import qualified Hasql.Encoders             as HE
+import qualified Hasql.Pool                 as P
+import qualified Hasql.Session              as H
+import qualified Hasql.Statement            as H
+import qualified Hasql.Transaction          as HT
+import qualified Hasql.Transaction.Sessions as HT
+
+import Text.InterpolatedString.Perl6 (q)
+
+import Protolude
+
+queryPgVersion :: H.Session PgVersion
+queryPgVersion = H.statement mempty $ H.Statement sql HE.noParams versionRow False
+  where
+    sql = "SELECT current_setting('server_version_num')::integer, current_setting('server_version')"
+    versionRow = HD.singleRow $ PgVersion <$> column HD.int4 <*> column HD.text
+
+queryDbSettings :: P.Pool -> Bool -> IO (Either P.UsageError [(Text, Text)])
+queryDbSettings pool prepared =
+  let transaction = if prepared then HT.transaction else HT.unpreparedTransaction in
+  P.use pool . transaction HT.ReadCommitted HT.Read $
+    HT.statement mempty dbSettingsStatement
+
+-- | Get db settings from the connection role. Global settings will be overridden by database specific settings.
+dbSettingsStatement :: H.Statement () [(Text, Text)]
+dbSettingsStatement = H.Statement sql HE.noParams decodeSettings False
+  where
+    sql = [q|
+      with
+      role_setting as (
+        select setdatabase, unnest(setconfig) as setting from pg_catalog.pg_db_role_setting
+        where setrole = current_user::regrole::oid
+          and setdatabase in (0, (select oid from pg_catalog.pg_database where datname = current_catalog))
+      ),
+      kv_settings as (
+        select setdatabase, split_part(setting, '=', 1) as k, split_part(setting, '=', 2) as value from role_setting
+        where setting like 'pgrst.%'
+      )
+      select distinct on (key) replace(k, 'pgrst.', '') as key, value
+      from kv_settings
+      order by key, setdatabase desc;
+    |]
+    decodeSettings = HD.rowList $ (,) <$> column HD.text <*> column HD.text
+
+column :: HD.Value a -> HD.Row a
+column = HD.column . HD.nonNullable

src/PostgREST/Config/JSPath.hs

@@ -0,0 +1,59 @@
+{-|
+Module      : PostgREST.Types
+Description : PostgREST common types and functions used by the rest of the modules
+-}
+{-# LANGUAGE DuplicateRecordFields #-}
+
+module PostgREST.Config.JSPath
+  ( JSPath
+  , JSPathExp(..)
+  , pRoleClaimKey
+  ) where
+
+import qualified Text.ParserCombinators.Parsec as P
+
+import Data.Either.Combinators       (mapLeft)
+import Text.ParserCombinators.Parsec ((<?>))
+import Text.Read                     (read)
+
+import qualified GHC.Show (show)
+
+import Protolude      hiding (toS)
+import Protolude.Conv (toS)
+
+
+-- | full jspath, e.g. .property[0].attr.detail
+type JSPath = [JSPathExp]
+
+-- | jspath expression, e.g. .property, .property[0] or ."property-dash"
+data JSPathExp
+  = JSPKey Text
+  | JSPIdx Int
+
+instance Show JSPathExp where
+  -- TODO: this needs to be quoted properly for special chars
+  show (JSPKey k) = "." <> show k
+  show (JSPIdx i) = "[" <> show i <> "]"
+
+-- Used for the config value "role-claim-key"
+pRoleClaimKey :: Text -> Either Text JSPath
+pRoleClaimKey selStr =
+  mapLeft show $ P.parse pJSPath ("failed to parse role-claim-key value (" <> toS selStr <> ")") (toS selStr)
+
+pJSPath :: P.Parser JSPath
+pJSPath = toJSPath <$> (period *> pPath `P.sepBy` period <* P.eof)
+  where
+    toJSPath :: [(Text, Maybe Int)] -> JSPath
+    toJSPath = concatMap (\(key, idx) -> JSPKey key : maybeToList (JSPIdx <$> idx))
+    period = P.char '.' <?> "period (.)"
+    pPath :: P.Parser (Text, Maybe Int)
+    pPath = (,) <$> pJSPKey <*> P.optionMaybe pJSPIdx
+
+pJSPKey :: P.Parser Text
+pJSPKey = toS <$> P.many1 (P.alphaNum <|> P.oneOf "_$@") <|> pQuotedValue <?> "attribute name [a..z0..9_$@])"
+
+pJSPIdx :: P.Parser Int
+pJSPIdx = P.char '[' *> (read <$> P.many1 P.digit) <* P.char ']' <?> "array index [0..n]"
+
+pQuotedValue :: P.Parser Text
+pQuotedValue = toS <$> (P.char '"' *> P.many (P.noneOf "\"") <* P.char '"')

src/PostgREST/Config/PgVersion.hs

@@ -0,0 +1,60 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric  #-}
+module PostgREST.Config.PgVersion
+  ( PgVersion(..)
+  , minimumPgVersion
+  , pgVersion95
+  , pgVersion96
+  , pgVersion100
+  , pgVersion109
+  , pgVersion110
+  , pgVersion112
+  , pgVersion114
+  , pgVersion121
+  , pgVersion130
+  ) where
+
+import qualified Data.Aeson as JSON
+
+import Protolude
+
+
+data PgVersion = PgVersion
+  { pgvNum  :: Int32
+  , pgvName :: Text
+  }
+  deriving (Eq, Generic, JSON.ToJSON)
+
+instance Ord PgVersion where
+  (PgVersion v1 _) `compare` (PgVersion v2 _) = v1 `compare` v2
+
+-- | Tells the minimum PostgreSQL version required by this version of PostgREST
+minimumPgVersion :: PgVersion
+minimumPgVersion = pgVersion95
+
+pgVersion95 :: PgVersion
+pgVersion95 = PgVersion 90500 "9.5"
+
+pgVersion96 :: PgVersion
+pgVersion96 = PgVersion 90600 "9.6"
+
+pgVersion100 :: PgVersion
+pgVersion100 = PgVersion 100000 "10"
+
+pgVersion109 :: PgVersion
+pgVersion109 = PgVersion 100009 "10.9"
+
+pgVersion110 :: PgVersion
+pgVersion110 = PgVersion 110000 "11.0"
+
+pgVersion112 :: PgVersion
+pgVersion112 = PgVersion 110002 "11.2"
+
+pgVersion114 :: PgVersion
+pgVersion114 = PgVersion 110004 "11.4"
+
+pgVersion121 :: PgVersion
+pgVersion121 = PgVersion 120001 "12.1"
+
+pgVersion130 :: PgVersion
+pgVersion130 = PgVersion 130000 "13.0"

src/PostgREST/Config/Proxy.hs

@@ -0,0 +1,78 @@
+{-|
+Module      : PostgREST.Private.ProxyUri
+Description : Proxy Uri validator
+-}
+module PostgREST.Config.Proxy
+  ( Proxy(..)
+  , isMalformedProxyUri
+  , toURI
+  ) where
+
+import Data.Maybe  (fromJust)
+import Data.Text   (pack, toLower)
+import Network.URI (URI (..), URIAuth (..), isAbsoluteURI, parseURI)
+
+import Protolude      hiding (Proxy, dropWhile, get, intercalate,
+                       toLower, toS, (&))
+import Protolude.Conv (toS)
+
+data Proxy = Proxy
+  { proxyScheme :: Text
+  , proxyHost   :: Text
+  , proxyPort   :: Integer
+  , proxyPath   :: Text
+  }
+
+{-|
+  Test whether a proxy uri is malformed or not.
+  A valid proxy uri should be an absolute uri without query and user info,
+  only http(s) schemes are valid, port number range is 1-65535.
+
+  For example
+  http://postgrest.com/openapi.json
+  https://postgrest.com:8080/openapi.json
+-}
+isMalformedProxyUri :: Text -> Bool
+isMalformedProxyUri uri
+  | isAbsoluteURI (toS uri) = not $ isUriValid $ toURI uri
+  | otherwise = True
+
+toURI :: Text -> URI
+toURI uri = fromJust $ parseURI (toS uri)
+
+isUriValid:: URI -> Bool
+isUriValid = fAnd [isSchemeValid, isQueryValid, isAuthorityValid]
+
+fAnd :: [a -> Bool] -> a -> Bool
+fAnd fs x = all ($ x) fs
+
+isSchemeValid :: URI -> Bool
+isSchemeValid URI {uriScheme = s}
+  | toLower (pack s) == "https:" = True
+  | toLower (pack s) == "http:" = True
+  | otherwise = False
+
+isQueryValid :: URI -> Bool
+isQueryValid URI {uriQuery = ""} = True
+isQueryValid _                   = False
+
+isAuthorityValid :: URI -> Bool
+isAuthorityValid URI {uriAuthority = a}
+  | isJust a = fAnd [isUserInfoValid, isHostValid, isPortValid] $ fromJust a
+  | otherwise = False
+
+isUserInfoValid :: URIAuth -> Bool
+isUserInfoValid URIAuth {uriUserInfo = ""} = True
+isUserInfoValid _                          = False
+
+isHostValid :: URIAuth -> Bool
+isHostValid URIAuth {uriRegName = ""} = False
+isHostValid _                         = True
+
+isPortValid :: URIAuth -> Bool
+isPortValid URIAuth {uriPort = ""} = True
+isPortValid URIAuth {uriPort = (':':p)} =
+  case readMaybe p of
+    Just i  -> i > (0 :: Integer) && i < 65536
+    Nothing -> False
+isPortValid _ = False

src/PostgREST/ContentType.hs

@@ -0,0 +1,64 @@
+{-# LANGUAGE DuplicateRecordFields #-}
+
+module PostgREST.ContentType
+  ( ContentType(..)
+  , toHeader
+  , toMime
+  , decodeContentType
+  ) where
+
+import qualified Data.ByteString          as BS
+import qualified Data.ByteString.Internal as BS (c2w)
+
+import Network.HTTP.Types.Header (Header, hContentType)
+
+import Protolude
+
+-- | Enumeration of currently supported response content types
+data ContentType
+  = CTApplicationJSON
+  | CTSingularJSON
+  | CTTextCSV
+  | CTTextPlain
+  | CTOpenAPI
+  | CTUrlEncoded
+  | CTOctetStream
+  | CTAny
+  | CTOther ByteString
+  deriving (Eq)
+
+-- | Convert from ContentType to a full HTTP Header
+toHeader :: ContentType -> Header
+toHeader ct = (hContentType, toMime ct <> charset)
+  where
+    charset = case ct of
+      CTOctetStream -> mempty
+      CTOther _     -> mempty
+      _             -> "; charset=utf-8"
+
+-- | Convert from ContentType to a ByteString representing the mime type
+toMime :: ContentType -> ByteString
+toMime CTApplicationJSON = "application/json"
+toMime CTTextCSV         = "text/csv"
+toMime CTTextPlain       = "text/plain"
+toMime CTOpenAPI         = "application/openapi+json"
+toMime CTSingularJSON    = "application/vnd.pgrst.object+json"
+toMime CTUrlEncoded      = "application/x-www-form-urlencoded"
+toMime CTOctetStream     = "application/octet-stream"
+toMime CTAny             = "*/*"
+toMime (CTOther ct)      = ct
+
+-- | Convert from ByteString to ContentType. Warning: discards MIME parameters
+decodeContentType :: BS.ByteString -> ContentType
+decodeContentType ct =
+  case BS.takeWhile (/= BS.c2w ';') ct of
+    "application/json"                  -> CTApplicationJSON
+    "text/csv"                          -> CTTextCSV
+    "text/plain"                        -> CTTextPlain
+    "application/openapi+json"          -> CTOpenAPI
+    "application/vnd.pgrst.object+json" -> CTSingularJSON
+    "application/vnd.pgrst.object"      -> CTSingularJSON
+    "application/x-www-form-urlencoded" -> CTUrlEncoded
+    "application/octet-stream"          -> CTOctetStream
+    "*/*"                               -> CTAny
+    ct'                                 -> CTOther ct'

src/PostgREST/DbRequestBuilder.hs

@@ -1,324 +0,0 @@
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE DuplicateRecordFields    #-}
-module PostgREST.DbRequestBuilder (
-  readRequest
-, mutateRequest
-, fieldNames
-) where
-
-import           Control.Applicative
-import           Control.Arrow             ((***))
-import           Control.Lens.Getter       (view)
-import           Control.Lens.Tuple        (_1)
-import qualified Data.ByteString.Char8     as BS
-import           Data.List                 (delete)
-import           Data.Maybe                (fromJust)
-import           Data.Text                 (isInfixOf)
-import           Data.Tree
-import           Data.Either.Combinators   (mapLeft)
-
-import           Network.Wai
-
-import           Data.Foldable (foldr1)
-import qualified Data.HashMap.Strict       as M
-
-import           PostgREST.ApiRequest   ( ApiRequest(..)
-                                        , PreferRepresentation(..)
-                                        , Action(..), Target(..)
-                                        , PreferRepresentation (..)
-                                        )
-import           PostgREST.Error           (apiRequestError)
-import           PostgREST.Parsers
-import           PostgREST.RangeQuery      (NonnegRange, restrictRange)
-import           PostgREST.QueryBuilder (getJoinFilters, sourceCTEName)
-import           PostgREST.Types
-
-import           Protolude                hiding (from, dropWhile, drop)
-import           Text.Regex.TDFA         ((=~))
-import           Unsafe                  (unsafeHead)
-
-readRequest :: Maybe Integer -> [Relation] -> M.HashMap Text ProcDescription -> ApiRequest -> Either Response ReadRequest
-readRequest maxRows allRels allProcs apiRequest  =
-  mapLeft apiRequestError $
-  treeRestrictRange maxRows =<<
-  augumentRequestWithJoin schema relations =<<
-  parseReadRequest
-  where
-    (schema, rootTableName) = fromJust $ -- Make it safe
-      let target = iTarget apiRequest in
-      case target of
-        (TargetIdent (QualifiedIdentifier s t) ) -> Just (s, t)
-        (TargetProc  (QualifiedIdentifier s proc) ) -> Just (s, tName)
-          where
-            retType = pdReturnType <$> M.lookup proc allProcs
-            tName = case retType of
-              Just (SetOf (Composite qi)) -> qiName qi
-              Just (Single (Composite qi)) -> qiName qi
-              _ -> proc
-
-        _ -> Nothing
-
-    action :: Action
-    action = iAction apiRequest
-
-    parseReadRequest :: Either ApiRequestError ReadRequest
-    parseReadRequest = addFiltersOrdersRanges apiRequest <*>
-      pRequestSelect rootName selStr
-      where
-        selStr = iSelect apiRequest
-        rootName = if action == ActionRead
-          then rootTableName
-          else sourceCTEName
-
-    relations :: [Relation]
-    relations = case action of
-      ActionCreate -> fakeSourceRelations ++ allRels
-      ActionUpdate -> fakeSourceRelations ++ allRels
-      ActionDelete -> fakeSourceRelations ++ allRels
-      ActionInvoke -> fakeSourceRelations ++ allRels
-      _       -> allRels
-      where fakeSourceRelations = mapMaybe (toSourceRelation rootTableName) allRels -- see comment in toSourceRelation
-
-treeRestrictRange :: Maybe Integer -> ReadRequest -> Either ApiRequestError ReadRequest
-treeRestrictRange maxRows_ request = pure $ nodeRestrictRange maxRows_ `fmap` request
-  where
-    nodeRestrictRange :: Maybe Integer -> ReadNode -> ReadNode
-    nodeRestrictRange m (q@Select {range_=r}, i) = (q{range_=restrictRange m r }, i)
-
-augumentRequestWithJoin :: Schema ->  [Relation] ->  ReadRequest -> Either ApiRequestError ReadRequest
-augumentRequestWithJoin schema allRels request =
-  addRelations schema allRels Nothing request
-  >>= addJoinFilters schema
-
-addRelations :: Schema -> [Relation] -> Maybe ReadRequest -> ReadRequest -> Either ApiRequestError ReadRequest
-addRelations schema allRelations parentNode (Node readNode@(query, (name, _, alias, relationDetail)) forest) =
-  case parentNode of
-    (Just (Node (Select{from=[parentNodeTable]}, (_, _, _, _)) _)) ->
-      Node <$> readNode' <*> forest'
-      where
-        forest' = updateForest $ hush node'
-        node' = Node <$> readNode' <*> pure forest
-        readNode' = addRel readNode <$> rel
-        rel :: Either ApiRequestError Relation
-        rel = note (NoRelationBetween parentNodeTable name)
-            $ findRelation schema name parentNodeTable relationDetail
-            where
-              
-              findRelation s nodeTableName parentNodeTableName Nothing =
-                find (\r ->
-                  s == tableSchema (relTable r) && -- match schema for relation table
-                  s == tableSchema (relFTable r) && -- match schema for relation foriegn table
-                  (
-
-                    -- (request)        => projects { ..., clients{...} }
-                    -- will match
-                    -- (relation type)  => parent
-                    -- (entity)         => clients  {id}
-                    -- (foriegn entity) => projects {client_id}
-                    (
-                      nodeTableName == tableName (relTable r) && -- match relation table name
-                      parentNodeTableName == tableName (relFTable r) -- match relation foreign table name
-                    ) ||
-
-
-                    -- (request)        => projects { ..., client_id{...} }
-                    -- will match
-                    -- (relation type)  => parent
-                    -- (entity)         => clients  {id}
-                    -- (foriegn entity) => projects {client_id}
-                    (
-                      parentNodeTableName == tableName (relFTable r) &&
-                      length (relFColumns r) == 1 &&
-                      nodeTableName `colMatches` (colName . unsafeHead . relFColumns) r
-                    )
-
-                    -- (request)        => project_id { ..., client_id{...} }
-                    -- will match
-                    -- (relation type)  => parent
-                    -- (entity)         => clients  {id}
-                    -- (foriegn entity) => projects {client_id}
-                    -- this case works becasue before reaching this place
-                    -- addRelation will turn project_id to project so the above condition will match
-                  )
-                ) allRelations
-              
-              findRelation s nodeTableName parentNodeTableName (Just rd) = 
-                find (\r ->
-                  s == tableSchema (relTable r) && -- match schema for relation table
-                  s == tableSchema (relFTable r) && -- match schema for relation foriegn table
-                  (
-
-                    -- (request)        => clients { ..., project.client_id{...} }
-                    -- will match
-                    -- (relation type)  => parent
-                    -- (entity)         => clients  {id}
-                    -- (foriegn entity) => projects {client_id}
-                    (
-                      nodeTableName == tableName (relTable r) && -- match relation table name
-                      parentNodeTableName == tableName (relFTable r) && -- && -- match relation foreign table name
-                      length (relColumns r) == 1 &&
-                      rd == (colName . unsafeHead . relColumns) r
-                    ) 
-                    ||
-
-
-                    -- (request)        => tasks { ..., users.tasks_users{...} }
-                    -- will match
-                    -- (relation type)  => many
-                    -- (entity)         => users
-                    -- (foriegn entity) => tasks
-                    (
-                      relType r == Many &&
-                      nodeTableName == tableName (relTable r) && -- match relation table name
-                      parentNodeTableName == tableName (relFTable r) && -- match relation foreign table name
-                      rd == tableName (fromJust (relLTable r))
-                    ) 
-                  )
-                ) allRelations
-              n `colMatches` rc = (toS ("^" <> rc <> "_?(?:|[iI][dD]|[fF][kK])$") :: BS.ByteString) =~ (toS n :: BS.ByteString)
-        addRel :: (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail)) -> Relation -> (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail))
-        addRel (query', (n, _, a, _)) r = (query' {from=fromRelation}, (n, Just r, a, Nothing))
-          where fromRelation = map (\t -> if t == n then tableName (relTable r) else t) (from query')
-
-    _ -> n' <$> updateForest (Just (n' forest))
-      where
-        n' = Node (query, (name, Just r, alias, Nothing))
-        t = Table schema name Nothing True -- !!! TODO find another way to get the table from the query
-        r = Relation t [] t [] Root Nothing Nothing Nothing
-  where
-    updateForest :: Maybe ReadRequest -> Either ApiRequestError [ReadRequest]
-    updateForest n = mapM (addRelations schema allRelations n) forest
-
-addJoinFilters :: Schema -> ReadRequest -> Either ApiRequestError ReadRequest
-addJoinFilters schema (Node node@(query, nodeProps@(_, relation, _, _)) forest) =
-  case relation of
-    Just Relation{relType=Root} -> Node node  <$> updatedForest -- this is the root node
-    Just Relation{relType=Parent} -> Node node <$> updatedForest
-    Just rel@Relation{relType=Child} -> Node (augmentQuery rel, nodeProps) <$> updatedForest
-    Just rel@Relation{relType=Many, relLTable=(Just linkTable)} ->
-      let rq = augmentQuery rel in
-      Node (rq{from=tableName linkTable:from rq}, nodeProps) <$> updatedForest
-    _ -> Left UnknownRelation
-  where
-    updatedForest = mapM (addJoinFilters schema) forest
-    augmentQuery rel = foldr addFilterToReadQuery query (getJoinFilters rel)
-    addFilterToReadQuery flt rq@Select{where_=lf} = rq{where_=addFilterToLogicForest flt lf}::ReadQuery
-
-addFiltersOrdersRanges :: ApiRequest -> Either ApiRequestError (ReadRequest -> ReadRequest)
-addFiltersOrdersRanges apiRequest = foldr1 (liftA2 (.)) [
-    flip (foldr addFilter) <$> filters,
-    flip (foldr addOrder) <$> orders,
-    flip (foldr addRange) <$> ranges,
-    flip (foldr addLogicTree) <$> logicForest
-  ]
-  {-
-  The esence of what is going on above is that we are composing tree functions
-  of type (ReadRequest->ReadRequest) that are in (Either ParseError a) context
-  -}
-  where
-    filters :: Either ApiRequestError [(EmbedPath, Filter)]
-    filters = mapM pRequestFilter flts
-    logicForest :: Either ApiRequestError [(EmbedPath, LogicTree)]
-    logicForest = mapM pRequestLogicTree logFrst
-    action = iAction apiRequest
-    -- there can be no filters on the root table when we are doing insert/update/delete
-    (flts, logFrst)
-      | action == ActionRead || action == ActionInvoke = (iFilters apiRequest, iLogic apiRequest)
-      | otherwise = join (***) (filter (( "." `isInfixOf` ) . fst)) (iFilters apiRequest, iLogic apiRequest)
-    orders :: Either ApiRequestError [(EmbedPath, [OrderTerm])]
-    orders = mapM pRequestOrder $ iOrder apiRequest
-    ranges :: Either ApiRequestError [(EmbedPath, NonnegRange)]
-    ranges = mapM pRequestRange $ M.toList $ iRange apiRequest
-
-addFilterToNode :: Filter -> ReadRequest -> ReadRequest
-addFilterToNode flt (Node (q@Select {where_=lf}, i) f) = Node (q{where_=addFilterToLogicForest flt lf}::ReadQuery, i) f
-
-addFilter :: (EmbedPath, Filter) -> ReadRequest -> ReadRequest
-addFilter = addProperty addFilterToNode
-
-addOrderToNode :: [OrderTerm] -> ReadRequest -> ReadRequest
-addOrderToNode o (Node (q,i) f) = Node (q{order=Just o}, i) f
-
-addOrder :: (EmbedPath, [OrderTerm]) -> ReadRequest -> ReadRequest
-addOrder = addProperty addOrderToNode
-
-addRangeToNode :: NonnegRange -> ReadRequest -> ReadRequest
-addRangeToNode r (Node (q,i) f) = Node (q{range_=r}, i) f
-
-addRange :: (EmbedPath, NonnegRange) -> ReadRequest -> ReadRequest
-addRange = addProperty addRangeToNode
-
-addLogicTreeToNode :: LogicTree -> ReadRequest -> ReadRequest
-addLogicTreeToNode t (Node (q@Select{where_=lf},i) f) = Node (q{where_=t:lf}::ReadQuery, i) f
-
-addLogicTree :: (EmbedPath, LogicTree) -> ReadRequest -> ReadRequest
-addLogicTree = addProperty addLogicTreeToNode
-
-addProperty :: (a -> ReadRequest -> ReadRequest) -> (EmbedPath, a) -> ReadRequest -> ReadRequest
-addProperty f ([], a) n = f a n
-addProperty f (path, a) (Node rn forest) =
-  case targetNode of
-    Nothing -> Node rn forest -- the property is silenty dropped in the Request does not contain the required path
-    Just tn -> Node rn (addProperty f (remainingPath, a) tn:restForest)
-  where
-    targetNodeName:remainingPath = path
-    (targetNode,restForest) = splitForest targetNodeName forest
-    splitForest :: NodeName -> Forest ReadNode -> (Maybe ReadRequest, Forest ReadNode)
-    splitForest name forst =
-      case maybeNode of
-        Nothing -> (Nothing,forest)
-        Just node -> (Just node, delete node forest)
-      where
-        maybeNode :: Maybe ReadRequest
-        maybeNode = find fnd forst
-          where
-            fnd :: ReadRequest -> Bool
-            fnd (Node (_,(n,_,_,_)) _) = n == name
-
--- in a relation where one of the tables mathces "TableName"
--- replace the name to that table with pg_source
--- this "fake" relations is needed so that in a mutate query
--- we can look a the "returning *" part which is wrapped with a "with"
--- as just another table that has relations with other tables
-toSourceRelation :: TableName -> Relation -> Maybe Relation
-toSourceRelation mt r@(Relation t _ ft _ _ rt _ _)
-  | mt == tableName t = Just $ r {relTable=t {tableName=sourceCTEName}}
-  | mt == tableName ft = Just $ r {relFTable=t {tableName=sourceCTEName}}
-  | Just mt == (tableName <$> rt) = Just $ r {relLTable=(\tbl -> tbl {tableName=sourceCTEName}) <$> rt}
-  | otherwise = Nothing
-
-mutateRequest :: ApiRequest -> [FieldName] -> Either Response MutateRequest
-mutateRequest apiRequest fldNames = mapLeft apiRequestError $
-  case action of
-    ActionCreate -> Right $ Insert rootTableName payload returnings
-    ActionUpdate -> Update rootTableName <$> pure payload <*> combinedLogic <*> pure returnings
-    ActionDelete -> Delete rootTableName <$> combinedLogic <*> pure returnings
-    _        -> Left UnsupportedVerb
-  where
-    action = iAction apiRequest
-    payload = fromJust $ iPayload apiRequest
-    rootTableName = -- TODO: Make it safe
-      let target = iTarget apiRequest in
-      case target of
-        (TargetIdent (QualifiedIdentifier _ t) ) -> t
-        _ -> undefined
-    returnings = if iPreferRepresentation apiRequest == None then [] else fldNames
-    filters = map snd <$> mapM pRequestFilter mutateFilters
-    logic = map snd <$> mapM pRequestLogicTree logicFilters
-    combinedLogic = foldr addFilterToLogicForest <$> logic <*> filters
-    -- update/delete filters can be only on the root table
-    (mutateFilters, logicFilters) = join (***) onlyRoot (iFilters apiRequest, iLogic apiRequest)
-    onlyRoot = filter (not . ( "." `isInfixOf` ) . fst)
-
-fieldNames :: ReadRequest -> [FieldName]
-fieldNames (Node (sel, _) forest) =
-  map (fst . view _1) (select sel) ++ map colName fks
-  where
-    fks = concatMap (fromMaybe [] . f) forest
-    f (Node (_, (_, Just Relation{relFColumns=cols, relType=Parent}, _, _)) _) = Just cols
-    f _ = Nothing
-
--- Traditional filters(e.g. id=eq.1) are added as root nodes of the LogicTree
--- they are later concatenated with AND in the QueryBuilder
-addFilterToLogicForest :: Filter -> [LogicTree] -> [LogicTree]
-addFilterToLogicForest flt lf = Stmnt flt : lf

src/PostgREST/DbStructure/Identifiers.hs

@@ -0,0 +1,42 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric  #-}
+
+module PostgREST.DbStructure.Identifiers
+  ( QualifiedIdentifier(..)
+  , Schema
+  , TableName
+  , FieldName
+  , toQi
+  ) where
+
+import qualified Data.Aeson as JSON
+import qualified Data.Text  as T
+import qualified GHC.Show
+
+import Protolude
+
+
+-- | Represents a pg identifier with a prepended schema name "schema.table".
+-- When qiSchema is "", the schema is defined by the pg search_path.
+data QualifiedIdentifier = QualifiedIdentifier
+  { qiSchema :: Schema
+  , qiName   :: TableName
+  }
+  deriving (Eq, Ord, Generic, JSON.ToJSON, JSON.ToJSONKey)
+
+instance Hashable QualifiedIdentifier
+
+instance Show QualifiedIdentifier where
+  show (QualifiedIdentifier s i) =
+    (if T.null s then mempty else toS s <> ".") <> toS i
+
+-- TODO: Handle a case where the QI comes like this: "my.fav.schema"."my.identifier"
+-- Right now it only handles the schema.identifier case
+toQi :: Text -> QualifiedIdentifier
+toQi txt = case T.drop 1 <$> T.breakOn "." txt of
+  (i, "") -> QualifiedIdentifier mempty i
+  (s, i)  -> QualifiedIdentifier s i
+
+type Schema = Text
+type TableName = Text
+type FieldName = Text

src/PostgREST/DbStructure/Proc.hs

@@ -0,0 +1,97 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric  #-}
+
+module PostgREST.DbStructure.Proc
+  ( PgArg(..)
+  , PgType(..)
+  , ProcDescription(..)
+  , ProcVolatility(..)
+  , ProcsMap
+  , RetType(..)
+  , procReturnsScalar
+  , procReturnsSingle
+  , procTableName
+  , specifiedProcArgs
+  ) where
+
+import qualified Data.Aeson          as JSON
+import qualified Data.HashMap.Strict as M
+import qualified Data.Set            as S
+
+import PostgREST.DbStructure.Identifiers (FieldName,
+                                          QualifiedIdentifier (..),
+                                          Schema, TableName)
+
+import Protolude
+
+
+data PgArg = PgArg
+  { pgaName :: Text
+  , pgaType :: Text
+  , pgaReq  :: Bool
+  , pgaVar  :: Bool
+  }
+  deriving (Eq, Ord, Generic, JSON.ToJSON)
+
+data PgType
+  = Scalar
+  | Composite QualifiedIdentifier
+  deriving (Eq, Ord, Generic, JSON.ToJSON)
+
+data RetType
+  = Single PgType
+  | SetOf PgType
+  deriving (Eq, Ord, Generic, JSON.ToJSON)
+
+data ProcVolatility
+  = Volatile
+  | Stable
+  | Immutable
+  deriving (Eq, Ord, Generic, JSON.ToJSON)
+
+data ProcDescription = ProcDescription
+  { pdSchema      :: Schema
+  , pdName        :: Text
+  , pdDescription :: Maybe Text
+  , pdArgs        :: [PgArg]
+  , pdReturnType  :: RetType
+  , pdVolatility  :: ProcVolatility
+  , pdHasVariadic :: Bool
+  }
+  deriving (Eq, Generic, JSON.ToJSON)
+
+-- Order by least number of args in the case of overloaded functions
+instance Ord ProcDescription where
+  ProcDescription schema1 name1 des1 args1 rt1 vol1 hasVar1 `compare` ProcDescription schema2 name2 des2 args2 rt2 vol2 hasVar2
+    | schema1 == schema2 && name1 == name2 && length args1 < length args2  = LT
+    | schema2 == schema2 && name1 == name2 && length args1 > length args2  = GT
+    | otherwise = (schema1, name1, des1, args1, rt1, vol1, hasVar1) `compare` (schema2, name2, des2, args2, rt2, vol2, hasVar2)
+
+-- | A map of all procs, all of which can be overloaded(one entry will have more than one ProcDescription).
+-- | It uses a HashMap for a faster lookup.
+type ProcsMap = M.HashMap QualifiedIdentifier [ProcDescription]
+
+{-|
+  Search the procedure parameters by matching them with the specified keys.
+  If the key doesn't match a parameter, a parameter with a default type "text" is assumed.
+-}
+specifiedProcArgs :: S.Set FieldName -> ProcDescription -> [PgArg]
+specifiedProcArgs keys proc =
+  (\k -> fromMaybe (PgArg k "text" True False) (find ((==) k . pgaName) (pdArgs proc))) <$> S.toList keys
+
+procReturnsScalar :: ProcDescription -> Bool
+procReturnsScalar proc = case proc of
+  ProcDescription{pdReturnType = (Single Scalar)} -> True
+  ProcDescription{pdReturnType = (SetOf Scalar)}  -> True
+  _                                               -> False
+
+procReturnsSingle :: ProcDescription -> Bool
+procReturnsSingle proc = case proc of
+  ProcDescription{pdReturnType = (Single _)} -> True
+  _                                          -> False
+
+procTableName :: ProcDescription -> Maybe TableName
+procTableName proc = case pdReturnType proc of
+  SetOf  (Composite qi) -> Just $ qiName qi
+  Single (Composite qi) -> Just $ qiName qi
+  _                     -> Nothing

src/PostgREST/DbStructure/Relationship.hs

@@ -0,0 +1,62 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric  #-}
+
+module PostgREST.DbStructure.Relationship
+  ( Cardinality(..)
+  , PrimaryKey(..)
+  , Relationship(..)
+  , Junction(..)
+  , isSelfReference
+  ) where
+
+import qualified Data.Aeson as JSON
+
+import PostgREST.DbStructure.Table (Column (..), Table (..))
+
+import Protolude
+
+
+-- | Relationship between two tables.
+--
+-- The order of the relColumns and relForeignColumns should be maintained to get the
+-- join conditions right.
+--
+-- TODO merge relColumns and relForeignColumns to a tuple or Data.Bimap
+data Relationship = Relationship
+  { relTable          :: Table
+  , relColumns        :: [Column]
+  , relForeignTable   :: Table
+  , relForeignColumns :: [Column]
+  , relCardinality    :: Cardinality
+  }
+  deriving (Eq, Generic, JSON.ToJSON)
+
+-- | The relationship cardinality
+-- | https://en.wikipedia.org/wiki/Cardinality_(data_modeling)
+-- TODO: missing one-to-one
+data Cardinality
+  = O2M FKConstraint -- ^ one-to-many cardinality
+  | M2O FKConstraint -- ^ many-to-one cardinality
+  | M2M Junction     -- ^ many-to-many cardinality
+  deriving (Eq, Generic, JSON.ToJSON)
+
+type FKConstraint = Text
+
+-- | Junction table on an M2M relationship
+data Junction = Junction
+  { junTable       :: Table
+  , junConstraint1 :: FKConstraint
+  , junColumns1    :: [Column]
+  , junConstraint2 :: FKConstraint
+  , junColumns2    :: [Column]
+  }
+  deriving (Eq, Generic, JSON.ToJSON)
+
+isSelfReference :: Relationship -> Bool
+isSelfReference r = relTable r == relForeignTable r
+
+data PrimaryKey = PrimaryKey
+  { pkTable :: Table
+  , pkName  :: Text
+  }
+  deriving (Generic, JSON.ToJSON)

src/PostgREST/DbStructure/Table.hs

@@ -0,0 +1,55 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric  #-}
+
+module PostgREST.DbStructure.Table
+  ( Column(..)
+  , Table(..)
+  , tableQi
+  ) where
+
+import qualified Data.Aeson as JSON
+
+import PostgREST.DbStructure.Identifiers (FieldName,
+                                          QualifiedIdentifier (..),
+                                          Schema, TableName)
+
+import Protolude
+
+
+data Table = Table
+  { tableSchema      :: Schema
+  , tableName        :: TableName
+  , tableDescription :: Maybe Text
+    -- The following fields identify what can be done on the table/view, they're not related to the privileges granted to it
+  , tableInsertable  :: Bool
+  , tableUpdatable   :: Bool
+  , tableDeletable   :: Bool
+  }
+  deriving (Show, Ord, Generic, JSON.ToJSON)
+
+instance Eq Table where
+  Table{tableSchema=s1,tableName=n1} == Table{tableSchema=s2,tableName=n2} = s1 == s2 && n1 == n2
+
+tableQi :: Table -> QualifiedIdentifier
+tableQi Table{tableSchema=s, tableName=n} = QualifiedIdentifier s n
+
+data Column = Column
+  { colTable       :: Table
+  , colName        :: FieldName
+  , colDescription :: Maybe Text
+  , colNullable    :: Bool
+  , colType        :: Text
+  , colMaxLen      :: Maybe Int32
+  , colDefault     :: Maybe Text
+  , colEnum        :: [Text]
+  }
+  deriving (Ord, Generic, JSON.ToJSON)
+
+instance Eq Column where
+  Column{colTable=t1,colName=n1} == Column{colTable=t2,colName=n2} = t1 == t2 && n1 == n2
+
+data PrimaryKey = PrimaryKey
+  { pkTable :: Table
+  , pkName  :: Text
+  }
+  deriving (Generic, JSON.ToJSON)

src/PostgREST/Error.hs

@@ -1,89 +1,86 @@
+{-|
+Module      : PostgREST.Error
+Description : PostgREST error HTTP responses
+-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
-{-# LANGUAGE FlexibleInstances    #-}
-{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE RecordWildCards #-}
 
-module PostgREST.Error (
-  apiRequestError
-, pgError
-, simpleError
-, singularityError
-, binaryFieldError
-, connectionLostError
-, encodeError
-) where
+module PostgREST.Error
+  ( errorResponseFor
+  , ApiRequestError(..)
+  , PgError(..)
+  , Error(..)
+  , errorPayload
+  , checkIsFatal
+  , singularityError
+  ) where
 
-import           Protolude
-import           Data.Aeson                ((.=))
 import qualified Data.Aeson                as JSON
-import           Data.Text                 (unwords)
+import qualified Data.Text                 as T
 import qualified Hasql.Pool                as P
 import qualified Hasql.Session             as H
-import           Network.HTTP.Types.Header
 import qualified Network.HTTP.Types.Status as HT
-import           Network.Wai               (Response, responseLBS)
-import           PostgREST.Types
 
-apiRequestError :: ApiRequestError -> Response
-apiRequestError err =
-  errorResponse status
-    [toHeader CTApplicationJSON] err
-  where
-    status =
-      case err of
-        ActionInappropriate -> HT.status405
-        UnsupportedVerb -> HT.status405
-        InvalidBody _ -> HT.status400
-        ParseRequestError _ _ -> HT.status400
-        NoRelationBetween _ _ -> HT.status400
-        InvalidRange -> HT.status416
-        UnknownRelation -> HT.status404
+import Data.Aeson  ((.=))
+import Network.Wai (Response, responseLBS)
 
-simpleError :: HT.Status -> [Header] -> Text -> Response
-simpleError status hdrs message =
-  errorResponse status (toHeader CTApplicationJSON : hdrs) $
-    JSON.object ["message" .= message]
+import Network.HTTP.Types.Header (Header)
 
-errorResponse :: JSON.ToJSON a => HT.Status -> [Header] -> a -> Response
-errorResponse status hdrs e =
-  responseLBS status hdrs $ encodeError e
+import           PostgREST.ContentType (ContentType (..))
+import qualified PostgREST.ContentType as ContentType
 
-pgError :: Bool -> P.UsageError -> Response
-pgError authed e =
-  let status = httpStatus authed e
-      jsonType = toHeader CTApplicationJSON
-      wwwAuth = ("WWW-Authenticate", "Bearer")
-      hdrs = if status == HT.status401
-                then [jsonType, wwwAuth]
-                else [jsonType] in
-  responseLBS status hdrs (encodeError e)
+import PostgREST.DbStructure.Proc         (PgArg (..),
+                                           ProcDescription (..))
+import PostgREST.DbStructure.Relationship (Cardinality (..),
+                                           Junction (..),
+                                           Relationship (..))
+import PostgREST.DbStructure.Table        (Column (..), Table (..))
 
-singularityError :: Integer -> Response
-singularityError numRows =
-  responseLBS HT.status406
-    [toHeader CTSingularJSON]
-    $ toS . formatGeneralError
-      "JSON object requested, multiple (or no) rows returned"
-      $ unwords
-        [ "Results contain", show numRows, "rows,"
-        , toS (toMime CTSingularJSON), "requires 1 row"
-        ]
-  where
-    formatGeneralError :: Text -> Text -> Text
-    formatGeneralError message details = toS . JSON.encode $
-      JSON.object ["message" .= message, "details" .= details]
+import Protolude      hiding (toS)
+import Protolude.Conv (toS, toSL)
 
 
-binaryFieldError :: Response
-binaryFieldError =
-  simpleError HT.status406 [] (toS (toMime CTOctetStream) <>
-  " requested but a single column was not selected")
+class (JSON.ToJSON a) => PgrstError a where
+  status   :: a -> HT.Status
+  headers  :: a -> [Header]
 
-connectionLostError :: Response
-connectionLostError =
-  simpleError HT.status503 [] "Database connection lost, retrying the connection."
+  errorPayload :: a -> LByteString
+  errorPayload = JSON.encode
 
-encodeError :: JSON.ToJSON a => a -> LByteString
-encodeError = JSON.encode
+  errorResponseFor :: a -> Response
+  errorResponseFor err = responseLBS (status err) (headers err) $ errorPayload err
+
+
+
+data ApiRequestError
+  = ActionInappropriate
+  | InvalidRange
+  | InvalidBody ByteString
+  | ParseRequestError Text Text
+  | NoRelBetween Text Text
+  | AmbiguousRelBetween Text Text [Relationship]
+  | AmbiguousRpc [ProcDescription]
+  | NoRpc Text Text [Text] Bool
+  | InvalidFilters
+  | UnacceptableSchema [Text]
+  | ContentTypeError [ByteString]
+  | UnsupportedVerb                -- Unreachable?
+
+instance PgrstError ApiRequestError where
+  status InvalidRange            = HT.status416
+  status InvalidFilters          = HT.status405
+  status (InvalidBody _)         = HT.status400
+  status UnsupportedVerb         = HT.status405
+  status ActionInappropriate     = HT.status405
+  status (ParseRequestError _ _) = HT.status400
+  status (NoRelBetween _ _)      = HT.status400
+  status AmbiguousRelBetween{}   = HT.status300
+  status (AmbiguousRpc _)        = HT.status300
+  status NoRpc{}                 = HT.status404
+  status (UnacceptableSchema _)  = HT.status406
+  status (ContentTypeError _)    = HT.status415
+
+  headers _ = [ContentType.toHeader CTApplicationJSON]
 
 instance JSON.ToJSON ApiRequestError where
   toJSON (ParseRequestError message details) = JSON.object [
@@ -94,78 +91,237 @@ instance JSON.ToJSON ApiRequestError where
     "message" .= (toS errorMessage :: Text)]
   toJSON InvalidRange = JSON.object [
     "message" .= ("HTTP Range error" :: Text)]
-  toJSON UnknownRelation = JSON.object [
-    "message" .= ("Unknown relation" :: Text)]
-  toJSON (NoRelationBetween parent child) = JSON.object [
-    "message" .= ("Could not find foreign keys between these entities, No relation found between " <> parent <> " and " <> child :: Text)]
+  toJSON (NoRelBetween parent child) = JSON.object [
+    "hint"    .= ("If a new foreign key between these entities was created in the database, try reloading the schema cache." :: Text),
+    "message" .= ("Could not find a relationship between " <> parent <> " and " <> child <> " in the schema cache" :: Text)]
+  toJSON (AmbiguousRelBetween parent child rels) = JSON.object [
+    "hint"    .= ("By following the 'details' key, disambiguate the request by changing the url to /origin?select=relationship(*) or /origin?select=target!relationship(*)" :: Text),
+    "message" .= ("More than one relationship was found for " <> parent <> " and " <> child :: Text),
+    "details" .= (compressedRel <$> rels) ]
+  toJSON (AmbiguousRpc procs)  = JSON.object [
+    "hint"    .= ("Overloaded functions with the same argument name but different types are not supported" :: Text),
+    "message" .= ("Could not choose the best candidate function between: " <> T.intercalate ", " [pdSchema p <> "." <> pdName p <> "(" <> T.intercalate ", " [pgaName a <> " => " <> pgaType a | a <- pdArgs p] <> ")" | p <- procs])]
+  toJSON (NoRpc schema procName payloadKeys hasPreferSingleObject)  = JSON.object [
+    "hint"    .= ("If a new function was created in the database with this name and arguments, try reloading the schema cache." :: Text),
+    "message" .= ("Could not find the " <> schema <> "." <> procName <> (if hasPreferSingleObject then " function with a single json or jsonb argument" else "(" <> T.intercalate ", " payloadKeys <> ")" <> " function") <> " in the schema cache")]
   toJSON UnsupportedVerb = JSON.object [
     "message" .= ("Unsupported HTTP verb" :: Text)]
+  toJSON InvalidFilters = JSON.object [
+    "message" .= ("Filters must include all and only primary key columns with 'eq' operators" :: Text)]
+  toJSON (UnacceptableSchema schemas) = JSON.object [
+    "message" .= ("The schema must be one of the following: " <> T.intercalate ", " schemas)]
+  toJSON (ContentTypeError cts)    = JSON.object [
+    "message" .= ("None of these Content-Types are available: " <> (toS . intercalate ", " . map toS) cts :: Text)]
+
+compressedRel :: Relationship -> JSON.Value
+compressedRel Relationship{..} =
+  let
+    fmtTbl Table{..} = tableSchema <> "." <> tableName
+    fmtEls els = "[" <> T.intercalate ", " els <> "]"
+  in
+  JSON.object $ [
+    "origin"      .= fmtTbl relTable
+  , "target"      .= fmtTbl relForeignTable
+  ] ++
+  case relCardinality of
+    M2M Junction{..} -> [
+        "cardinality" .= ("m2m" :: Text)
+      , "relationship" .= (fmtTbl junTable <> fmtEls [junConstraint1] <> fmtEls [junConstraint2])
+      ]
+    M2O cons -> [
+        "cardinality" .= ("m2o" :: Text)
+      , "relationship" .= (cons <> fmtEls (colName <$> relColumns) <> fmtEls (colName <$> relForeignColumns))
+      ]
+    O2M cons -> [
+        "cardinality" .= ("o2m" :: Text)
+      , "relationship" .= (cons <> fmtEls (colName <$> relColumns) <> fmtEls (colName <$> relForeignColumns))
+      ]
+
+data PgError = PgError Authenticated P.UsageError
+type Authenticated = Bool
+
+instance PgrstError PgError where
+  status (PgError authed usageError) = pgErrorStatus authed usageError
+
+  headers err =
+    if status err == HT.status401
+       then [ContentType.toHeader CTApplicationJSON, ("WWW-Authenticate", "Bearer") :: Header]
+       else [ContentType.toHeader CTApplicationJSON]
+
+instance JSON.ToJSON PgError where
+  toJSON (PgError _ usageError) = JSON.toJSON usageError
 
 instance JSON.ToJSON P.UsageError where
   toJSON (P.ConnectionError e) = JSON.object [
-    "code" .= ("" :: Text),
-    "message" .= ("Database connection error" :: Text),
-    "details" .= (toS $ fromMaybe "" e :: Text)]
+    "code"    .= ("" :: Text),
+    "message" .= ("Database connection error. Retrying the connection." :: Text),
+    "details" .= (toSL $ fromMaybe "" e :: Text)]
   toJSON (P.SessionError e) = JSON.toJSON e -- H.Error
 
-instance JSON.ToJSON H.Error where
-  toJSON (H.ResultError (H.ServerError c m d h)) = JSON.object [
-    "code" .= (toS c::Text),
-    "message" .= (toS m::Text),
-    "details" .= (fmap toS d::Maybe Text),
-    "hint" .= (fmap toS h::Maybe Text)]
+instance JSON.ToJSON H.QueryError where
+  toJSON (H.QueryError _ _ e) = JSON.toJSON e
+
+instance JSON.ToJSON H.CommandError where
+  toJSON (H.ResultError (H.ServerError c m d h)) = case toS c of
+    'P':'T':_ -> JSON.object [
+        "details" .= (fmap toS d :: Maybe Text),
+        "hint"    .= (fmap toS h :: Maybe Text)]
+
+    _         -> JSON.object [
+        "code"    .= (toS c      :: Text),
+        "message" .= (toS m      :: Text),
+        "details" .= (fmap toS d :: Maybe Text),
+        "hint"    .= (fmap toS h :: Maybe Text)]
+
   toJSON (H.ResultError (H.UnexpectedResult m)) = JSON.object [
-    "message" .= (m::Text)]
+    "message" .= (m :: Text)]
   toJSON (H.ResultError (H.RowError i H.EndOfInput)) = JSON.object [
-    "message" .= ("Row error: end of input"::Text),
-    "details" .=
-      ("Attempt to parse more columns than there are in the result"::Text),
-    "details" .= (("Row number " <> show i)::Text)]
+    "message" .= ("Row error: end of input" :: Text),
+    "details" .= ("Attempt to parse more columns than there are in the result" :: Text),
+    "hint"    .= (("Row number " <> show i) :: Text)]
   toJSON (H.ResultError (H.RowError i H.UnexpectedNull)) = JSON.object [
-    "message" .= ("Row error: unexpected null"::Text),
-    "details" .= ("Attempt to parse a NULL as some value."::Text),
-    "details" .= (("Row number " <> show i)::Text)]
+    "message" .= ("Row error: unexpected null" :: Text),
+    "details" .= ("Attempt to parse a NULL as some value." :: Text),
+    "hint"    .= (("Row number " <> show i) :: Text)]
   toJSON (H.ResultError (H.RowError i (H.ValueError d))) = JSON.object [
-    "message" .= ("Row error: Wrong value parser used"::Text),
+    "message" .= ("Row error: Wrong value parser used" :: Text),
     "details" .= d,
-    "details" .= (("Row number " <> show i)::Text)]
+    "hint"    .= (("Row number " <> show i) :: Text)]
   toJSON (H.ResultError (H.UnexpectedAmountOfRows i)) = JSON.object [
-    "message" .= ("Unexpected amount of rows"::Text),
+    "message" .= ("Unexpected amount of rows" :: Text),
     "details" .= i]
   toJSON (H.ClientError d) = JSON.object [
-    "message" .= ("Database client error"::Text),
-    "details" .= (fmap toS d::Maybe Text)]
+    "message" .= ("Database client error. Retrying the connection." :: Text),
+    "details" .= (fmap toS d :: Maybe Text)]
 
-httpStatus :: Bool -> P.UsageError -> HT.Status
-httpStatus _ (P.ConnectionError _) = HT.status503
-httpStatus authed (P.SessionError (H.ResultError (H.ServerError c _ _ _))) =
-  case toS c of
-    '0':'8':_ -> HT.status503 -- pg connection err
-    '0':'9':_ -> HT.status500 -- triggered action exception
-    '0':'L':_ -> HT.status403 -- invalid grantor
-    '0':'P':_ -> HT.status403 -- invalid role specification
-    "23503"   -> HT.status409 -- foreign_key_violation
-    "23505"   -> HT.status409 -- unique_violation
-    '2':'5':_ -> HT.status500 -- invalid tx state
-    '2':'8':_ -> HT.status403 -- invalid auth specification
-    '2':'D':_ -> HT.status500 -- invalid tx termination
-    '3':'8':_ -> HT.status500 -- external routine exception
-    '3':'9':_ -> HT.status500 -- external routine invocation
-    '3':'B':_ -> HT.status500 -- savepoint exception
-    '4':'0':_ -> HT.status500 -- tx rollback
-    '5':'3':_ -> HT.status503 -- insufficient resources
-    '5':'4':_ -> HT.status413 -- too complex
-    '5':'5':_ -> HT.status500 -- obj not on prereq state
-    '5':'7':_ -> HT.status500 -- operator intervention
-    '5':'8':_ -> HT.status500 -- system error
-    'F':'0':_ -> HT.status500 -- conf file error
-    'H':'V':_ -> HT.status500 -- foreign data wrapper error
-    "P0001"   -> HT.status400 -- default code for "raise"
-    'P':'0':_ -> HT.status500 -- PL/pgSQL Error
-    'X':'X':_ -> HT.status500 -- internal Error
-    "42883"   -> HT.status404 -- undefined function
-    "42P01"   -> HT.status404 -- undefined table
-    "42501"   -> if authed then HT.status403 else HT.status401 -- insufficient privilege
-    _         -> HT.status400
-httpStatus _ (P.SessionError (H.ResultError _)) = HT.status500
-httpStatus _ (P.SessionError (H.ClientError _)) = HT.status503
+pgErrorStatus :: Bool -> P.UsageError -> HT.Status
+pgErrorStatus _      (P.ConnectionError _)                                      = HT.status503
+pgErrorStatus _      (P.SessionError (H.QueryError _ _ (H.ClientError _)))      = HT.status503
+pgErrorStatus authed (P.SessionError (H.QueryError _ _ (H.ResultError rError))) =
+  case rError of
+    (H.ServerError c m _ _) ->
+      case toS c of
+        '0':'8':_ -> HT.status503 -- pg connection err
+        '0':'9':_ -> HT.status500 -- triggered action exception
+        '0':'L':_ -> HT.status403 -- invalid grantor
+        '0':'P':_ -> HT.status403 -- invalid role specification
+        "23503"   -> HT.status409 -- foreign_key_violation
+        "23505"   -> HT.status409 -- unique_violation
+        "25006"   -> HT.status405 -- read_only_sql_transaction
+        '2':'5':_ -> HT.status500 -- invalid tx state
+        '2':'8':_ -> HT.status403 -- invalid auth specification
+        '2':'D':_ -> HT.status500 -- invalid tx termination
+        '3':'8':_ -> HT.status500 -- external routine exception
+        '3':'9':_ -> HT.status500 -- external routine invocation
+        '3':'B':_ -> HT.status500 -- savepoint exception
+        '4':'0':_ -> HT.status500 -- tx rollback
+        '5':'3':_ -> HT.status503 -- insufficient resources
+        '5':'4':_ -> HT.status413 -- too complex
+        '5':'5':_ -> HT.status500 -- obj not on prereq state
+        '5':'7':_ -> HT.status500 -- operator intervention
+        '5':'8':_ -> HT.status500 -- system error
+        'F':'0':_ -> HT.status500 -- conf file error
+        'H':'V':_ -> HT.status500 -- foreign data wrapper error
+        "P0001"   -> HT.status400 -- default code for "raise"
+        'P':'0':_ -> HT.status500 -- PL/pgSQL Error
+        'X':'X':_ -> HT.status500 -- internal Error
+        "42883"   -> HT.status404 -- undefined function
+        "42P01"   -> HT.status404 -- undefined table
+        "42501"   -> if authed then HT.status403 else HT.status401 -- insufficient privilege
+        'P':'T':n -> fromMaybe HT.status500 (HT.mkStatus <$> readMaybe n <*> pure m)
+        _         -> HT.status400
+
+    _                       -> HT.status500
+
+checkIsFatal :: PgError -> Maybe Text
+checkIsFatal (PgError _ (P.ConnectionError e))
+  | isAuthFailureMessage = Just $ toS failureMessage
+  | otherwise = Nothing
+  where isAuthFailureMessage = "FATAL:  password authentication failed" `isPrefixOf` toS failureMessage
+        failureMessage = fromMaybe mempty e
+checkIsFatal (PgError _ (P.SessionError (H.QueryError _ _ (H.ResultError serverError))))
+  = case serverError of
+      -- Check for a syntax error (42601 is the pg code). This would mean the error is on our part somehow, so we treat it as fatal.
+      H.ServerError "42601" _ _ _
+        -> Just "Hint: This is probably a bug in PostgREST, please report it at https://github.com/PostgREST/postgrest/issues"
+      -- Check for a "prepared statement <name> already exists" error (Code 42P05: duplicate_prepared_statement).
+      -- This would mean that a connection pooler in transaction mode is being used
+      -- while prepared statements are enabled in the PostgREST configuration,
+      -- both of which are incompatible with each other.
+      H.ServerError "42P05" _ _ _
+        -> Just "Hint: If you are using connection poolers in transaction mode, try setting db-prepared-statements to false."
+      -- Check for a "transaction blocks not allowed in statement pooling mode" error (Code 08P01: protocol_violation).
+      -- This would mean that a connection pooler in statement mode is being used which is not supported in PostgREST.
+      H.ServerError "08P01" "transaction blocks not allowed in statement pooling mode" _ _
+        -> Just "Hint: Connection poolers in statement mode are not supported."
+      _ -> Nothing
+checkIsFatal _ = Nothing
+
+
+data Error
+  = GucHeadersError
+  | GucStatusError
+  | BinaryFieldError ContentType
+  | ConnectionLostError
+  | PutMatchingPkError
+  | PutRangeNotAllowedError
+  | JwtTokenMissing
+  | JwtTokenInvalid Text
+  | SingularityError Integer
+  | NotFound
+  | ApiRequestError ApiRequestError
+  | PgErr PgError
+
+instance PgrstError Error where
+  status GucHeadersError         = HT.status500
+  status GucStatusError          = HT.status500
+  status (BinaryFieldError _)    = HT.status406
+  status ConnectionLostError     = HT.status503
+  status PutMatchingPkError      = HT.status400
+  status PutRangeNotAllowedError = HT.status400
+  status JwtTokenMissing         = HT.status500
+  status (JwtTokenInvalid _)     = HT.unauthorized401
+  status (SingularityError _)    = HT.status406
+  status NotFound                = HT.status404
+  status (PgErr err)             = status err
+  status (ApiRequestError err)   = status err
+
+  headers (SingularityError _)     = [ContentType.toHeader CTSingularJSON]
+  headers (JwtTokenInvalid m)      = [ContentType.toHeader CTApplicationJSON, invalidTokenHeader m]
+  headers (PgErr err)              = headers err
+  headers (ApiRequestError err)    = headers err
+  headers _                        = [ContentType.toHeader CTApplicationJSON]
+
+instance JSON.ToJSON Error where
+  toJSON GucHeadersError           = JSON.object [
+    "message" .= ("response.headers guc must be a JSON array composed of objects with a single key and a string value" :: Text)]
+  toJSON GucStatusError           = JSON.object [
+    "message" .= ("response.status guc must be a valid status code" :: Text)]
+  toJSON (BinaryFieldError ct)          = JSON.object [
+    "message" .= ((toS (ContentType.toMime ct) <> " requested but more than one column was selected") :: Text)]
+  toJSON ConnectionLostError       = JSON.object [
+    "message" .= ("Database connection lost. Retrying the connection." :: Text)]
+
+  toJSON PutRangeNotAllowedError   = JSON.object [
+    "message" .= ("Range header and limit/offset querystring parameters are not allowed for PUT" :: Text)]
+  toJSON PutMatchingPkError        = JSON.object [
+    "message" .= ("Payload values do not match URL in primary key column(s)" :: Text)]
+
+  toJSON (SingularityError n)      = JSON.object [
+    "message" .= ("JSON object requested, multiple (or no) rows returned" :: Text),
+    "details" .= T.unwords ["Results contain", show n, "rows,", toS (ContentType.toMime CTSingularJSON), "requires 1 row"]]
+
+  toJSON JwtTokenMissing           = JSON.object [
+    "message" .= ("Server lacks JWT secret" :: Text)]
+  toJSON (JwtTokenInvalid message) = JSON.object [
+    "message" .= (message :: Text)]
+  toJSON NotFound = JSON.object []
+  toJSON (PgErr err) = JSON.toJSON err
+  toJSON (ApiRequestError err) = JSON.toJSON err
+
+invalidTokenHeader :: Text -> Header
+invalidTokenHeader m =
+  ("WWW-Authenticate", "Bearer error=\"invalid_token\", " <> "error_description=" <> encodeUtf8 (show m))
+
+singularityError :: (Integral a) => a -> Error
+singularityError = SingularityError . toInteger

src/PostgREST/GucHeader.hs

@@ -0,0 +1,37 @@
+module PostgREST.GucHeader
+  ( GucHeader
+  , unwrapGucHeader
+  , addHeadersIfNotIncluded
+  ) where
+
+import qualified Data.Aeson           as JSON
+import qualified Data.CaseInsensitive as CI
+import qualified Data.HashMap.Strict  as M
+
+import Network.HTTP.Types.Header (Header)
+
+import Protolude      hiding (toS)
+import Protolude.Conv (toS)
+
+
+{-|
+  Custom guc header, it's obtained by parsing the json in a:
+  `SET LOCAL "response.headers" = '[{"Set-Cookie": ".."}]'
+-}
+newtype GucHeader = GucHeader (CI.CI ByteString, ByteString)
+
+instance JSON.FromJSON GucHeader where
+  parseJSON (JSON.Object o) = case headMay (M.toList o) of
+    Just (k, JSON.String s) | M.size o == 1 -> pure $ GucHeader (CI.mk $ toS k, toS s)
+                            | otherwise     -> mzero
+    _ -> mzero
+  parseJSON _          = mzero
+
+unwrapGucHeader :: GucHeader -> Header
+unwrapGucHeader (GucHeader (k, v)) = (k, v)
+
+-- | Add headers not already included to allow the user to override them instead of duplicating them
+addHeadersIfNotIncluded :: [Header] -> [Header] -> [Header]
+addHeadersIfNotIncluded newHeaders initialHeaders =
+  filter (\(nk, _) -> isNothing $ find (\(ik, _) -> ik == nk) initialHeaders) newHeaders ++
+  initialHeaders

src/PostgREST/Middleware.hs

@@ -1,61 +1,183 @@
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE FlexibleContexts #-}
+{-|
+Module      : PostgREST.Middleware
+Description : Sets CORS policy. Also the PostgreSQL GUCs, role, search_path and pre-request function.
+-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.Middleware
+  ( runPgLocals
+  , pgrstFormat
+  , pgrstMiddleware
+  , defaultCorsPolicy
+  , corsPolicy
+  , optionalRollback
+  ) where
 
-module PostgREST.Middleware where
+import qualified Data.Aeson                           as JSON
+import qualified Data.ByteString.Char8                as BS
+import qualified Data.CaseInsensitive                 as CI
+import qualified Data.HashMap.Strict                  as M
+import qualified Data.Text                            as T
+import qualified Hasql.Decoders                       as HD
+import qualified Hasql.DynamicStatements.Snippet      as H hiding
+                                                           (sql)
+import qualified Hasql.DynamicStatements.Statement    as H
+import qualified Hasql.Transaction                    as H
+import qualified Network.HTTP.Types.Header            as HTTP
+import qualified Network.Wai                          as Wai
+import qualified Network.Wai.Logger                   as Wai
+import qualified Network.Wai.Middleware.Cors          as Wai
+import qualified Network.Wai.Middleware.Gzip          as Wai
+import qualified Network.Wai.Middleware.RequestLogger as Wai
+import qualified Network.Wai.Middleware.Static        as Wai
 
-import           Crypto.JWT
-import           Data.Aeson                    (Value (..))
-import qualified Data.HashMap.Strict           as M
-import qualified Hasql.Transaction             as H
+import Data.Function             (id)
+import Data.List                 (lookup)
+import Data.Scientific           (FPFormat (..), formatScientific,
+                                  isInteger)
+import Network.HTTP.Types.Status (Status, status400, status500,
+                                  statusCode)
+import System.IO.Unsafe          (unsafePerformIO)
+import System.Log.FastLogger     (toLogStr)
 
-import           Network.HTTP.Types.Status     (unauthorized401, status500)
-import           Network.Wai                   (Application, Response)
-import           Network.Wai.Middleware.Cors   (cors)
-import           Network.Wai.Middleware.Gzip   (def, gzip)
-import           Network.Wai.Middleware.Static (only, staticPolicy)
+import PostgREST.Config             (AppConfig (..), LogLevel (..))
+import PostgREST.Error              (Error, errorResponseFor)
+import PostgREST.GucHeader          (addHeadersIfNotIncluded)
+import PostgREST.Query.SqlFragment  (fromQi, intercalateSnippet,
+                                     unknownEncoder)
+import PostgREST.Request.ApiRequest (ApiRequest (..), Target (..))
 
-import           PostgREST.ApiRequest          (ApiRequest(..))
-import           PostgREST.Auth                (JWTAttempt(..))
-import           PostgREST.Config              (AppConfig (..), corsPolicy)
-import           PostgREST.Error               (simpleError)
-import           PostgREST.QueryBuilder        (pgFmtLit, unquoted, pgFmtEnvVar)
+import PostgREST.Request.Preferences
 
-import           Protolude                     hiding (concat, null)
+import Protolude      hiding (head, toS)
+import Protolude.Conv (toS)
 
-runWithClaims :: AppConfig -> JWTAttempt ->
-                 (ApiRequest -> H.Transaction Response) ->
-                 ApiRequest -> H.Transaction Response
-runWithClaims conf eClaims app req =
-  case eClaims of
-    JWTInvalid JWTExpired -> return $ unauthed "JWT expired"
-    JWTInvalid e -> return $ unauthed $ show e
-    JWTMissingSecret -> return $ simpleError status500 [] "Server lacks JWT secret"
-    JWTClaims claims -> do
-      H.sql $ toS.mconcat $ setRoleSql ++ claimsSql ++ headersSql ++ cookiesSql
-      mapM_ H.sql customReqCheck
-      app req
-      where
-        headersSql = map (pgFmtEnvVar "request.header.") $ iHeaders req
-        cookiesSql = map (pgFmtEnvVar "request.cookie.") $ iCookies req
-        claimsSql = map (pgFmtEnvVar "request.jwt.claim.") [(c,unquoted v) | (c,v) <- M.toList claimsWithRole]
-        setRoleSql = maybeToList $
-          (\r -> "set local role " <> r <> ";") . toS . pgFmtLit . unquoted <$> M.lookup "role" claimsWithRole
-        -- role claim defaults to anon if not specified in jwt
-        claimsWithRole = M.union claims (M.singleton "role" anon)
-        anon = String . toS $ configAnonRole conf
-        customReqCheck = (\f -> "select " <> toS f <> "();") <$> configReqCheck conf
+-- | Runs local(transaction scoped) GUCs for every request, plus the pre-request function
+runPgLocals :: AppConfig   -> M.HashMap Text JSON.Value ->
+               (ApiRequest -> ExceptT Error H.Transaction Wai.Response) ->
+               ApiRequest  -> ByteString -> ExceptT Error H.Transaction Wai.Response
+runPgLocals conf claims app req jsonDbS = do
+  lift $ H.statement mempty $ H.dynamicallyParameterized
+    ("select " <> intercalateSnippet ", " (searchPathSql : roleSql ++ claimsSql ++ [methodSql, pathSql] ++ headersSql ++ cookiesSql ++ appSettingsSql ++ specSql))
+    HD.noResult (configDbPreparedStatements conf)
+  lift $ traverse_ H.sql preReqSql
+  app req
   where
-    unauthed message = simpleError
-      unauthorized401
-      [( "WWW-Authenticate"
-        , "Bearer error=\"invalid_token\", " <>
-          "error_description=" <> show message
-      )]
-      message
+    methodSql = setConfigLocal mempty ("request.method", iMethod req)
+    pathSql = setConfigLocal mempty ("request.path", iPath req)
+    headersSql = setConfigLocal "request.header." <$> iHeaders req
+    cookiesSql = setConfigLocal "request.cookie." <$> iCookies req
+    claimsWithRole =
+      let anon = JSON.String . toS $ configDbAnonRole conf in -- role claim defaults to anon if not specified in jwt
+      M.union claims (M.singleton "role" anon)
+    claimsSql = setConfigLocal "request.jwt.claim." <$> [(toS c, toS $ unquoted v) | (c,v) <- M.toList claimsWithRole]
+    roleSql = maybeToList $ (\x -> setConfigLocal mempty ("role", toS $ unquoted x)) <$> M.lookup "role" claimsWithRole
+    appSettingsSql = setConfigLocal mempty <$> (join bimap toS <$> configAppSettings conf)
+    searchPathSql =
+      let schemas = T.intercalate ", " (iSchema req : configDbExtraSearchPath conf) in
+      setConfigLocal mempty ("search_path", toS schemas)
+    preReqSql = (\f -> "select " <> fromQi f <> "();") <$> configDbPreRequest conf
+    specSql = case iTarget req of
+      TargetProc{tpIsRootSpec=True} -> [setConfigLocal mempty ("request.spec", jsonDbS)]
+      _                             -> mempty
+    -- | Do a pg set_config(setting, value, true) call. This is equivalent to a SET LOCAL.
+    setConfigLocal :: ByteString -> (ByteString, ByteString) -> H.Snippet
+    setConfigLocal prefix (k, v) =
+      "set_config(" <> unknownEncoder (prefix <> k) <> ", " <> unknownEncoder v <> ", true)"
 
-defaultMiddle :: Application -> Application
-defaultMiddle =
-    gzip def
-  . cors corsPolicy
-  . staticPolicy (only [("favicon.ico", "static/favicon.ico")])
+-- | Log in apache format. Only requests that have a status greater than minStatus are logged.
+-- | There's no way to filter logs in the apache format on wai-extra: https://hackage.haskell.org/package/wai-extra-3.0.29.2/docs/Network-Wai-Middleware-RequestLogger.html#t:OutputFormat.
+-- | So here we copy wai-logger apacheLogStr function: https://github.com/kazu-yamamoto/logger/blob/a4f51b909a099c51af7a3f75cf16e19a06f9e257/wai-logger/Network/Wai/Logger/Apache.hs#L45
+-- | TODO: Add the ability to filter apache logs on wai-extra and remove this function.
+pgrstFormat :: Status -> Wai.OutputFormatter
+pgrstFormat minStatus date req status responseSize =
+  if status < minStatus
+    then mempty
+  else toLogStr (getSourceFromSocket req)
+    <> " - - ["
+    <> toLogStr date
+    <> "] \""
+    <> toLogStr (Wai.requestMethod req)
+    <> " "
+    <> toLogStr (Wai.rawPathInfo req <> Wai.rawQueryString req)
+    <> " "
+    <> toLogStr (show (Wai.httpVersion req)::Text)
+    <> "\" "
+    <> toLogStr (show (statusCode status)::Text)
+    <> " "
+    <> toLogStr (maybe "-" show responseSize::Text)
+    <> " \""
+    <> toLogStr (fromMaybe mempty $ Wai.requestHeaderReferer req)
+    <> "\" \""
+    <> toLogStr (fromMaybe mempty $ Wai.requestHeaderUserAgent req)
+    <> "\"\n"
+  where
+    getSourceFromSocket = BS.pack . Wai.showSockAddr . Wai.remoteHost
+
+pgrstMiddleware :: LogLevel -> Wai.Application -> Wai.Application
+pgrstMiddleware logLevel =
+    logger
+  . Wai.cors corsPolicy
+  . Wai.staticPolicy (Wai.only [("favicon.ico", "static/favicon.ico")])
+  where
+    logger = case logLevel of
+      LogCrit  -> id
+      LogError -> unsafePerformIO $ Wai.mkRequestLogger Wai.def { Wai.outputFormat = Wai.CustomOutputFormat $ pgrstFormat status500}
+      LogWarn  -> unsafePerformIO $ Wai.mkRequestLogger Wai.def { Wai.outputFormat = Wai.CustomOutputFormat $ pgrstFormat status400}
+      LogInfo  -> Wai.logStdout
+
+defaultCorsPolicy :: Wai.CorsResourcePolicy
+defaultCorsPolicy =  Wai.CorsResourcePolicy Nothing
+  ["GET", "POST", "PATCH", "PUT", "DELETE", "OPTIONS"] ["Authorization"] Nothing
+  (Just $ 60*60*24) False False True
+
+-- | CORS policy to be used in by Wai Cors middleware
+corsPolicy :: Wai.Request -> Maybe Wai.CorsResourcePolicy
+corsPolicy req = case lookup "origin" headers of
+  Just origin -> Just defaultCorsPolicy {
+      Wai.corsOrigins = Just ([origin], True)
+    , Wai.corsRequestHeaders = "Authentication" : accHeaders
+    , Wai.corsExposedHeaders = Just [
+        "Content-Encoding", "Content-Location", "Content-Range", "Content-Type"
+      , "Date", "Location", "Server", "Transfer-Encoding", "Range-Unit"
+      ]
+    }
+  Nothing -> Nothing
+  where
+    headers = Wai.requestHeaders req
+    accHeaders = case lookup "access-control-request-headers" headers of
+      Just hdrs -> map (CI.mk . toS . T.strip . toS) $ BS.split ',' hdrs
+      Nothing -> []
+
+unquoted :: JSON.Value -> Text
+unquoted (JSON.String t) = t
+unquoted (JSON.Number n) =
+  toS $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
+unquoted (JSON.Bool b) = show b
+unquoted v = toS $ JSON.encode v
+
+-- | Set a transaction to eventually roll back if requested and set respective
+-- headers on the response.
+optionalRollback
+  :: AppConfig
+  -> ApiRequest
+  -> ExceptT Error H.Transaction Wai.Response
+  -> ExceptT Error H.Transaction Wai.Response
+optionalRollback AppConfig{..} ApiRequest{..} transaction = do
+  resp <- catchError transaction $ return . errorResponseFor
+  when (shouldRollback || (configDbTxRollbackAll && not shouldCommit))
+    (lift H.condemn)
+  return $ Wai.mapResponseHeaders preferenceApplied resp
+  where
+    shouldCommit =
+      configDbTxAllowOverride && iPreferTransaction == Just Commit
+    shouldRollback =
+      configDbTxAllowOverride && iPreferTransaction == Just Rollback
+    preferenceApplied
+      | shouldCommit =
+          addHeadersIfNotIncluded
+            [(HTTP.hPreferenceApplied, BS.pack (show Commit))]
+      | shouldRollback =
+          addHeadersIfNotIncluded
+            [(HTTP.hPreferenceApplied, BS.pack (show Rollback))]
+      | otherwise =
+          identity

src/PostgREST/OpenAPI.hs

@@ -1,89 +1,132 @@
-{-# LANGUAGE OverloadedStrings #-}
+{-|
+Module      : PostgREST.OpenAPI
+Description : Generates the OpenAPI output
+-}
+{-# LANGUAGE LambdaCase      #-}
+{-# LANGUAGE NamedFieldPuns  #-}
+{-# LANGUAGE RecordWildCards #-}
+module PostgREST.OpenAPI (encode) where
 
-module PostgREST.OpenAPI (
-  encodeOpenAPI
-  , isMalformedProxyUri
-  , pickProxy
-  ) where
+import qualified Data.Aeson           as JSON
+import qualified Data.ByteString.Lazy as LBS
+import qualified Data.HashMap.Strict  as HashMap
+import qualified Data.HashSet.InsOrd  as Set
+import qualified Data.Text            as T
 
-import           Control.Arrow               ((&&&))
-import           Control.Lens
-import           Data.Aeson                  (decode, encode)
-import           Data.HashMap.Strict.InsOrd  (InsOrdHashMap, fromList)
-import           Data.Maybe                  (fromJust)
-import qualified Data.Set                    as Set
-import           Data.String                 (IsString (..))
-import           Data.Text                   (unpack, pack, init, tail, toLower, intercalate, append, dropWhile, breakOn)
-import           Network.URI                 (parseURI, isAbsoluteURI,
-                                              URI (..), URIAuth (..))
+import Control.Arrow              ((&&&))
+import Data.HashMap.Strict.InsOrd (InsOrdHashMap, fromList)
+import Data.Maybe                 (fromJust)
+import Data.String                (IsString (..))
+import Network.URI                (URI (..), URIAuth (..))
 
-import           Protolude hiding              ((&), Proxy, get, intercalate, dropWhile)
+import Control.Lens (at, (.~), (?~))
 
-import           Data.Swagger
+import Data.Swagger
 
-import           PostgREST.ApiRequest        (ContentType(..))
-import           PostgREST.Config            (prettyVersion)
-import           PostgREST.Types             (Table(..), Column(..), PgArg(..), ForeignKey(..),
-                                              PrimaryKey(..), Proxy(..), ProcDescription(..), toMime)
+import PostgREST.Config                   (AppConfig (..), Proxy (..),
+                                           isMalformedProxyUri, toURI)
+import PostgREST.DbStructure              (DbStructure (..),
+                                           tableCols, tablePKCols)
+import PostgREST.DbStructure.Proc         (PgArg (..),
+                                           ProcDescription (..))
+import PostgREST.DbStructure.Relationship (Cardinality (..),
+                                           PrimaryKey (..),
+                                           Relationship (..))
+import PostgREST.DbStructure.Table        (Column (..), Table (..))
+import PostgREST.Version                  (docsVersion, prettyVersion)
+
+import PostgREST.ContentType
+
+import Protolude      hiding (Proxy, get, toS)
+import Protolude.Conv (toS)
+
+encode :: AppConfig -> DbStructure -> [Table] -> HashMap.HashMap k [ProcDescription] -> Maybe Text -> LBS.ByteString
+encode conf dbStructure tables procs schemaDescription =
+  JSON.encode $
+    postgrestSpec
+      (dbRelationships dbStructure)
+      (concat $ HashMap.elems procs)
+      (openApiTableInfo dbStructure <$> tables)
+      (proxyUri conf)
+      schemaDescription
+      (dbPrimaryKeys dbStructure)
 
 makeMimeList :: [ContentType] -> MimeList
-makeMimeList cs = MimeList $ map (fromString . toS . toMime) cs
+makeMimeList cs = MimeList $ fmap (fromString . toS . toMime) cs
 
 toSwaggerType :: Text -> SwaggerType t
-toSwaggerType "text"      = SwaggerString
-toSwaggerType "integer"   = SwaggerInteger
-toSwaggerType "boolean"   = SwaggerBoolean
-toSwaggerType "numeric"   = SwaggerNumber
-toSwaggerType _           = SwaggerString
+toSwaggerType "character varying" = SwaggerString
+toSwaggerType "character"         = SwaggerString
+toSwaggerType "text"              = SwaggerString
+toSwaggerType "boolean"           = SwaggerBoolean
+toSwaggerType "smallint"          = SwaggerInteger
+toSwaggerType "integer"           = SwaggerInteger
+toSwaggerType "bigint"            = SwaggerInteger
+toSwaggerType "numeric"           = SwaggerNumber
+toSwaggerType "real"              = SwaggerNumber
+toSwaggerType "double precision"  = SwaggerNumber
+toSwaggerType _                   = SwaggerString
 
-makeTableDef :: [PrimaryKey] -> (Table, [Column], [Text]) -> (Text, Schema)
-makeTableDef pks (t, cs, _) =
+makeTableDef :: [Relationship] -> [PrimaryKey] -> (Table, [Column], [Text]) -> (Text, Schema)
+makeTableDef rels pks (t, cs, _) =
   let tn = tableName t in
       (tn, (mempty :: Schema)
         & description .~ tableDescription t
-        & type_ .~ SwaggerObject
-        & properties .~ fromList (map (makeProperty pks) cs))
+        & type_ ?~ SwaggerObject
+        & properties .~ fromList (fmap (makeProperty rels pks) cs)
+        & required .~ fmap colName (filter (not . colNullable) cs))
 
-makeProperty :: [PrimaryKey] -> Column -> (Text, Referenced Schema)
-makeProperty pks c = (colName c, Inline s)
+makeProperty :: [Relationship] -> [PrimaryKey] -> Column -> (Text, Referenced Schema)
+makeProperty rels pks c = (colName c, Inline s)
   where
-    e = if null $ colEnum c then Nothing else decode $ encode $ colEnum c
-    fk ForeignKey{fkCol=Column{colTable=Table{tableName=a}, colName=b}} =
-      intercalate "" ["This is a Foreign Key to `", a, ".", b, "`.<fk table='", a, "' column='", b, "'/>"]
+    e = if null $ colEnum c then Nothing else JSON.decode $ JSON.encode $ colEnum c
+    fk :: Maybe Text
+    fk =
+      let
+        -- Finds the relationship that has a single column foreign key
+        rel = find (\case
+          Relationship{relColumns, relCardinality=M2O _} -> [c] == relColumns
+          _                                                 -> False
+          ) rels
+        fCol = colName <$> (headMay . relForeignColumns =<< rel)
+        fTbl = tableName . relForeignTable <$> rel
+        fTblCol = (,) <$> fTbl <*> fCol
+      in
+        (\(a, b) -> T.intercalate "" ["This is a Foreign Key to `", a, ".", b, "`.<fk table='", a, "' column='", b, "'/>"]) <$> fTblCol
     pk :: Bool
     pk = any (\p -> pkTable p == colTable c && pkName p == colName c) pks
     n = catMaybes
       [ Just "Note:"
       , if pk then Just "This is a Primary Key.<pk/>" else Nothing
-      , fk <$> colFK c
+      , fk
       ]
     d =
       if length n > 1 then
-        Just $ append (fromMaybe "" ((`append` "\n\n") <$> colDescription c)) (intercalate "\n" n)
+        Just $ T.append (maybe "" (`T.append` "\n\n") $ colDescription c) (T.intercalate "\n" n)
       else
         colDescription c
     s =
       (mempty :: Schema)
-        & default_ .~ (decode . toS =<< colDefault c)
+        & default_ .~ (JSON.decode . toS =<< colDefault c)
         & description .~ d
         & enum_ .~ e
         & format ?~ colType c
         & maxLength .~ (fromIntegral <$> colMaxLen c)
-        & type_ .~ toSwaggerType (colType c)
+        & type_ ?~ toSwaggerType (colType c)
 
 makeProcSchema :: ProcDescription -> Schema
 makeProcSchema pd =
   (mempty :: Schema)
   & description .~ pdDescription pd
-  & type_ .~ SwaggerObject
-  & properties .~ fromList (map makeProcProperty (pdArgs pd))
-  & required .~ map pgaName (filter pgaReq (pdArgs pd))
+  & type_ ?~ SwaggerObject
+  & properties .~ fromList (fmap makeProcProperty (pdArgs pd))
+  & required .~ fmap pgaName (filter pgaReq (pdArgs pd))
 
 makeProcProperty :: PgArg -> (Text, Referenced Schema)
-makeProcProperty (PgArg n t _) = (n, Inline s)
+makeProcProperty (PgArg n t _ _) = (n, Inline s)
   where
     s = (mempty :: Schema)
-          & type_ .~ toSwaggerType t
+          & type_ ?~ toSwaggerType t
           & format ?~ t
 
 makePreferParam :: [Text] -> Param
@@ -94,15 +137,15 @@ makePreferParam ts =
   & required    ?~ False
   & schema .~ ParamOther ((mempty :: ParamOtherSchema)
     & in_ .~ ParamHeader
-    & type_ .~ SwaggerString
-    & enum_ .~ decode (encode ts))
+    & type_ ?~ SwaggerString
+    & enum_ .~ JSON.decode (JSON.encode ts))
 
 makeProcParam :: ProcDescription -> [Referenced Param]
 makeProcParam pd =
   [ Inline $ (mempty :: Param)
     & name     .~ "args"
     & required ?~ True
-    & schema   .~ (ParamBody $ Inline $ makeProcSchema pd)
+    & schema   .~ ParamBody (Inline $ makeProcSchema pd)
   , Ref $ Reference "preferParams"
   ]
 
@@ -117,43 +160,50 @@ makeParamDefs ti =
       & required    ?~ False
       & schema .~ ParamOther ((mempty :: ParamOtherSchema)
         & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
+  , ("on_conflict", (mempty :: Param)
+      & name        .~ "on_conflict"
+      & description ?~ "On Conflict"
+      & required    ?~ False
+      & schema .~ ParamOther ((mempty :: ParamOtherSchema)
+        & in_ .~ ParamQuery
+        & type_ ?~ SwaggerString))
   , ("order", (mempty :: Param)
       & name        .~ "order"
       & description ?~ "Ordering"
       & required    ?~ False
       & schema .~ ParamOther ((mempty :: ParamOtherSchema)
         & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
   , ("range", (mempty :: Param)
       & name        .~ "Range"
       & description ?~ "Limiting and Pagination"
       & required    ?~ False
       & schema .~ ParamOther ((mempty :: ParamOtherSchema)
         & in_ .~ ParamHeader
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
   , ("rangeUnit", (mempty :: Param)
       & name        .~ "Range-Unit"
       & description ?~ "Limiting and Pagination"
       & required    ?~ False
       & schema .~ ParamOther ((mempty :: ParamOtherSchema)
         & in_ .~ ParamHeader
-        & type_ .~ SwaggerString
-        & default_ .~ decode "\"items\""))
+        & type_ ?~ SwaggerString
+        & default_ .~ JSON.decode "\"items\""))
   , ("offset", (mempty :: Param)
       & name        .~ "offset"
       & description ?~ "Limiting and Pagination"
       & required    ?~ False
       & schema .~ ParamOther ((mempty :: ParamOtherSchema)
         & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
   , ("limit", (mempty :: Param)
       & name        .~ "limit"
       & description ?~ "Limiting and Pagination"
       & required    ?~ False
       & schema .~ ParamOther ((mempty :: ParamOtherSchema)
         & in_ .~ ParamQuery
-        & type_ .~ SwaggerString))
+        & type_ ?~ SwaggerString))
   ]
   <> concat [ makeObjectBody (tableName t) : makeRowFilters (tableName t) cs
             | (t, cs, _) <- ti
@@ -169,58 +219,66 @@ makeObjectBody tn =
 
 makeRowFilter :: Text -> Column -> (Text, Param)
 makeRowFilter tn c =
-  (intercalate "." ["rowFilter", tn, colName c], (mempty :: Param)
+  (T.intercalate "." ["rowFilter", tn, colName c], (mempty :: Param)
     & name .~ colName c
     & description .~ colDescription c
     & required ?~ False
     & schema .~ ParamOther ((mempty :: ParamOtherSchema)
       & in_ .~ ParamQuery
-      & type_ .~ SwaggerString
+      & type_ ?~ SwaggerString
       & format ?~ colType c))
 
 makeRowFilters :: Text -> [Column] -> [(Text, Param)]
-makeRowFilters tn = map (makeRowFilter tn)
+makeRowFilters tn = fmap (makeRowFilter tn)
 
 makePathItem :: (Table, [Column], [Text]) -> (FilePath, PathItem)
-makePathItem (t, cs, _) = ("/" ++ unpack tn, p $ tableInsertable t)
+makePathItem (t, cs, _) = ("/" ++ T.unpack tn, p $ tableInsertable t || tableUpdatable t || tableDeletable t)
   where
     -- Use first line of table description as summary; rest as description (if present)
     -- We strip leading newlines from description so that users can include a blank line between summary and description
-    (tSum, tDesc) = fmap fst &&& fmap (dropWhile (=='\n') . snd) $
-                    breakOn "\n" <$> tableDescription t
+    (tSum, tDesc) = fmap fst &&& fmap (T.dropWhile (=='\n') . snd) $
+                    T.breakOn "\n" <$> tableDescription t
     tOp = (mempty :: Operation)
       & tags .~ Set.fromList [tn]
       & summary .~ tSum
       & description .~ mfilter (/="") tDesc
     getOp = tOp
-      & parameters .~ map ref (rs <> ["select", "order", "range", "rangeUnit", "offset", "limit", "preferCount"])
+      & parameters .~ fmap ref (rs <> ["select", "order", "range", "rangeUnit", "offset", "limit", "preferCount"])
       & at 206 ?~ "Partial Content"
       & at 200 ?~ Inline ((mempty :: Response)
         & description .~ "OK"
-        & schema ?~ (Ref $ Reference $ tableName t)
+        & schema ?~ Inline (mempty
+          & type_ ?~ SwaggerArray
+          & items ?~ SwaggerItemsObject (Ref $ Reference $ tableName t)
         )
+      )
     postOp = tOp
-      & parameters .~ map ref ["body." <> tn, "preferReturn"]
+      & parameters .~ fmap ref ["body." <> tn, "select", "preferReturn"]
       & at 201 ?~ "Created"
     patchOp = tOp
-      & parameters .~ map ref (rs <> ["body." <> tn, "preferReturn"])
+      & parameters .~ fmap ref (rs <> ["body." <> tn, "preferReturn"])
       & at 204 ?~ "No Content"
     deletOp = tOp
-      & parameters .~ map ref (rs <> ["preferReturn"])
+      & parameters .~ fmap ref (rs <> ["preferReturn"])
       & at 204 ?~ "No Content"
     pr = (mempty :: PathItem) & get ?~ getOp
     pw = pr & post ?~ postOp & patch ?~ patchOp & delete ?~ deletOp
     p False = pr
     p True  = pw
     tn = tableName t
-    rs = [ intercalate "." ["rowFilter", tn, colName c ] | c <- cs ]
+    rs = [ T.intercalate "." ["rowFilter", tn, colName c ] | c <- cs ]
     ref = Ref . Reference
 
 makeProcPathItem :: ProcDescription -> (FilePath, PathItem)
 makeProcPathItem pd = ("/rpc/" ++ toS (pdName pd), pe)
   where
+    -- Use first line of proc description as summary; rest as description (if present)
+    -- We strip leading newlines from description so that users can include a blank line between summary and description
+    (pSum, pDesc) = fmap fst &&& fmap (T.dropWhile (=='\n') . snd) $
+                    T.breakOn "\n" <$> pdDescription pd
     postOp = (mempty :: Operation)
-      & description .~ pdDescription pd
+      & summary .~ pSum
+      & description .~ mfilter (/="") pDesc
       & parameters .~ makeProcParam pd
       & tags .~ Set.fromList ["(rpc) " <> pdName pd]
       & produces ?~ makeMimeList [CTApplicationJSON, CTSingularJSON]
@@ -240,7 +298,7 @@ makeRootPathItem = ("/", p)
 
 makePathItems :: [ProcDescription] -> [(Table, [Column], [Text])] -> InsOrdHashMap FilePath PathItem
 makePathItems pds ti = fromList $ makeRootPathItem :
-  map makePathItem ti ++ map makeProcPathItem pds
+  fmap makePathItem ti ++ fmap makeProcPathItem pds
 
 escapeHostName :: Text -> Text
 escapeHostName "*"  = "0.0.0.0"
@@ -250,9 +308,9 @@ escapeHostName "*6" = "0.0.0.0"
 escapeHostName "!6" = "0.0.0.0"
 escapeHostName h    = h
 
-postgrestSpec :: [ProcDescription] -> [(Table, [Column], [Text])] -> (Text, Text, Integer, Text) -> Maybe Text -> [PrimaryKey] -> Swagger
-postgrestSpec pds ti (s, h, p, b) sd pks = (mempty :: Swagger)
-  & basePath ?~ unpack b
+postgrestSpec :: [Relationship] -> [ProcDescription] -> [(Table, [Column], [Text])] -> (Text, Text, Integer, Text) -> Maybe Text -> [PrimaryKey] -> Swagger
+postgrestSpec rels pds ti (s, h, p, b) sd pks = (mempty :: Swagger)
+  & basePath ?~ T.unpack b
   & schemes ?~ [s']
   & info .~ ((mempty :: Info)
       & version .~ prettyVersion
@@ -260,46 +318,25 @@ postgrestSpec pds ti (s, h, p, b) sd pks = (mempty :: Swagger)
       & description ?~ d)
   & externalDocs ?~ ((mempty :: ExternalDocs)
     & description ?~ "PostgREST Documentation"
-    & url .~ URL "https://postgrest.com/en/latest/api.html")
+    & url .~ URL ("https://postgrest.org/en/" <> docsVersion <> "/api.html"))
   & host .~ h'
-  & definitions .~ fromList (map (makeTableDef pks) ti)
+  & definitions .~ fromList (makeTableDef rels pks <$> ti)
   & parameters .~ fromList (makeParamDefs ti)
   & paths .~ makePathItems pds ti
   & produces .~ makeMimeList [CTApplicationJSON, CTSingularJSON, CTTextCSV]
   & consumes .~ makeMimeList [CTApplicationJSON, CTSingularJSON, CTTextCSV]
     where
       s' = if s == "http" then Http else Https
-      h' = Just $ Host (unpack $ escapeHostName h) (Just (fromInteger p))
+      h' = Just $ Host (T.unpack $ escapeHostName h) (Just (fromInteger p))
       d = fromMaybe "This is a dynamic API generated by PostgREST" sd
 
-encodeOpenAPI :: [ProcDescription] -> [(Table, [Column], [Text])] -> (Text, Text, Integer, Text) -> Maybe Text -> [PrimaryKey] ->  LByteString
-encodeOpenAPI pds ti uri sd pks = encode $ postgrestSpec pds ti uri sd pks
-
-{-|
-  Test whether a proxy uri is malformed or not.
-  A valid proxy uri should be an absolute uri without query and user info,
-  only http(s) schemes are valid, port number range is 1-65535.
-
-  For example
-  http://postgrest.com/openapi.json
-  https://postgrest.com:8080/openapi.json
--}
-isMalformedProxyUri :: Maybe Text -> Bool
-isMalformedProxyUri Nothing =  False
-isMalformedProxyUri (Just uri)
-  | isAbsoluteURI (toS uri) = not $ isUriValid $ toURI uri
-  | otherwise = True
-
-toURI :: Text -> URI
-toURI uri = fromJust $ parseURI (toS uri)
-
 pickProxy :: Maybe Text -> Maybe Proxy
 pickProxy proxy
   | isNothing proxy = Nothing
   -- should never happen
   -- since the request would have been rejected by the middleware if proxy uri
   -- is malformed
-  | isMalformedProxyUri proxy = Nothing
+  | isMalformedProxyUri $ fromMaybe mempty proxy = Nothing
   | otherwise = Just Proxy {
     proxyScheme = scheme
   , proxyHost = host'
@@ -308,53 +345,31 @@ pickProxy proxy
   }
  where
    uri = toURI $ fromJust proxy
-   scheme = init $ toLower $ pack $ uriScheme uri
+   scheme = T.init $ T.toLower $ T.pack $ uriScheme uri
    path URI {uriPath = ""} =  "/"
-   path URI {uriPath = p} = p
-   path' = pack $ path uri
+   path URI {uriPath = p}  = p
+   path' = T.pack $ path uri
    authority = fromJust $ uriAuthority uri
-   host' = pack $ uriRegName authority
+   host' = T.pack $ uriRegName authority
    port' = uriPort authority
    readPort = fromMaybe 80 . readMaybe
    port'' :: Integer
    port'' = case (port', scheme) of
-             ("", "http") -> 80
+             ("", "http")  -> 80
              ("", "https") -> 443
-             _ -> readPort $ unpack $ tail $ pack port'
+             _             -> readPort $ T.unpack $ T.tail $ T.pack port'
 
-isUriValid:: URI -> Bool
-isUriValid = fAnd [isSchemeValid, isQueryValid, isAuthorityValid]
+proxyUri :: AppConfig -> (Text, Text, Integer, Text)
+proxyUri AppConfig{..} =
+  case pickProxy $ toS <$> configOpenApiServerProxyUri of
+    Just Proxy{..} ->
+      (proxyScheme, proxyHost, proxyPort, proxyPath)
+    Nothing ->
+      ("http", configServerHost, toInteger configServerPort, "/")
 
-fAnd :: [a -> Bool] -> a -> Bool
-fAnd fs x = all ($x) fs
-
-isSchemeValid :: URI -> Bool
-isSchemeValid URI {uriScheme = s}
-  | toLower (pack s) == "https:" = True
-  | toLower (pack s) == "http:" = True
-  | otherwise = False
-
-isQueryValid :: URI -> Bool
-isQueryValid URI {uriQuery = ""} = True
-isQueryValid _ = False
-
-isAuthorityValid :: URI -> Bool
-isAuthorityValid URI {uriAuthority = a}
-  | isJust a = fAnd [isUserInfoValid, isHostValid, isPortValid] $ fromJust a
-  | otherwise = False
-
-isUserInfoValid :: URIAuth -> Bool
-isUserInfoValid URIAuth {uriUserInfo = ""} = True
-isUserInfoValid _ = False
-
-isHostValid :: URIAuth -> Bool
-isHostValid URIAuth {uriRegName = ""} = False
-isHostValid _ = True
-
-isPortValid :: URIAuth -> Bool
-isPortValid URIAuth {uriPort = ""} = True
-isPortValid URIAuth {uriPort = (':':p)} =
-  case readMaybe p of
-    Just i -> i > (0 :: Integer) && i < 65536
-    Nothing -> False
-isPortValid _ = False
+openApiTableInfo :: DbStructure -> Table -> (Table, [Column], [Text])
+openApiTableInfo dbStructure table =
+  ( table
+  , tableCols dbStructure (tableSchema table) (tableName table)
+  , tablePKCols dbStructure (tableSchema table) (tableName table)
+  )

src/PostgREST/Parsers.hs

@@ -1,223 +0,0 @@
-module PostgREST.Parsers where
-
-import           Protolude                     hiding (try, intercalate, replace)
-import           Control.Monad                 ((>>))
-import           Data.Foldable                 (foldl1)
-import qualified Data.HashMap.Strict           as M
-import           Data.Text                     (intercalate, replace, strip)
-import           Data.List                     (init, last)
-import           Data.Tree
-import           Data.Either.Combinators       (mapLeft)
-import           PostgREST.RangeQuery          (NonnegRange,allRange)
-import           PostgREST.Types
-import           Text.ParserCombinators.Parsec hiding (many, (<|>))
-import           Text.Parsec.Error
-
-pRequestSelect :: Text -> Text -> Either ApiRequestError ReadRequest
-pRequestSelect rootName selStr =
-  mapError $ parse (pReadRequest rootName) ("failed to parse select parameter (" <> toS selStr <> ")") (toS selStr)
-
-pRequestFilter :: (Text, Text) -> Either ApiRequestError (EmbedPath, Filter)
-pRequestFilter (k, v) = mapError $ (,) <$> path <*> (Filter <$> fld <*> oper)
-  where
-    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
-    oper = parse (pOperation pVText pVTextL) ("failed to parse filter (" ++ toS v ++ ")") $ toS v
-    path = fst <$> treePath
-    fld = snd <$> treePath
-
-pRequestOrder :: (Text, Text) -> Either ApiRequestError (EmbedPath, [OrderTerm])
-pRequestOrder (k, v) = mapError $ (,) <$> path <*> ord'
-  where
-    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
-    path = fst <$> treePath
-    ord' = parse pOrder ("failed to parse order (" ++ toS v ++ ")") $ toS v
-
-pRequestRange :: (ByteString, NonnegRange) -> Either ApiRequestError (EmbedPath, NonnegRange)
-pRequestRange (k, v) = mapError $ (,) <$> path <*> pure v
-  where
-    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
-    path = fst <$> treePath
-
-pRequestLogicTree :: (Text, Text) -> Either ApiRequestError (EmbedPath, LogicTree)
-pRequestLogicTree (k, v) = mapError $ (,) <$> embedPath <*> logicTree
-  where
-    path = parse pLogicPath ("failed to parser logic path (" ++ toS k ++ ")") $ toS k
-    embedPath = fst <$> path
-    op = snd <$> path
-    -- Concat op and v to make pLogicTree argument regular, in the form of "op(.,.)"
-    logicTree = join $ parse pLogicTree ("failed to parse logic tree (" ++ toS v ++ ")") . toS <$> ((<>) <$> op <*> pure v)
-
-ws :: Parser Text
-ws = toS <$> many (oneOf " \t")
-
-lexeme :: Parser a -> Parser a
-lexeme p = ws *> p <* ws
-
-pReadRequest :: Text -> Parser ReadRequest
-pReadRequest rootNodeName = do
-  fieldTree <- pFieldForest
-  return $ foldr treeEntry (Node (readQuery, (rootNodeName, Nothing, Nothing, Nothing)) []) fieldTree
-  where
-    readQuery = Select [] [rootNodeName] [] Nothing allRange
-    treeEntry :: Tree SelectItem -> ReadRequest -> ReadRequest
-    treeEntry (Node fld@((fn, _),_,alias,relationDetail) fldForest) (Node (q, i) rForest) =
-      case fldForest of
-        [] -> Node (q {select=fld:select q}, i) rForest
-        _  -> Node (q, i) newForest
-          where
-            newForest =
-              foldr treeEntry (Node (Select [] [fn] [] Nothing allRange, (fn, Nothing, alias, relationDetail)) []) fldForest:rForest
-
-pTreePath :: Parser (EmbedPath, Field)
-pTreePath = do
-  p <- pFieldName `sepBy1` pDelimiter
-  jp <- optionMaybe pJsonPath
-  return (init p, (last p, jp))
-
-pFieldForest :: Parser [Tree SelectItem]
-pFieldForest = pFieldTree `sepBy1` lexeme (char ',')
-
-pFieldTree :: Parser (Tree SelectItem)
-pFieldTree =  try (Node <$> pRelationSelect <*> between (char '{') (char '}') pFieldForest)
-          <|> try (Node <$> pRelationSelect <*> between (char '(') (char ')') pFieldForest)
-          <|> Node <$> pFieldSelect <*> pure []
-
-pStar :: Parser Text
-pStar = toS <$> (string "*" *> pure ("*"::ByteString))
-
-
-pFieldName :: Parser Text
-pFieldName = do
-  matches <- (many1 (letter <|> digit <|> oneOf "_") `sepBy1` dash) <?> "field name (* or [a..z0..9_])"
-  return $ intercalate "-" $ map toS matches
-  where
-    isDash :: GenParser Char st ()
-    isDash = try ( char '-' >> notFollowedBy (char '>') )
-    dash :: Parser Char
-    dash = isDash *> pure '-'
-
-
-pJsonPathStep :: Parser Text
-pJsonPathStep = toS <$> try (string "->" *> pFieldName)
-
-pJsonPath :: Parser [Text]
-pJsonPath = (<>) <$> many pJsonPathStep <*> ( (:[]) <$> (string "->>" *> pFieldName) )
-
-pField :: Parser Field
-pField = lexeme $ (,) <$> pFieldName <*> optionMaybe pJsonPath
-
-aliasSeparator :: Parser ()
-aliasSeparator = char ':' >> notFollowedBy (char ':')
-
-pRelationSelect :: Parser SelectItem
-pRelationSelect = lexeme $ try ( do
-    alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
-    fld <- pField
-    relationDetail <- optionMaybe ( try( char '.' *> pFieldName ) )
-
-    return (fld, Nothing, alias, relationDetail)
-  )
-
-pFieldSelect :: Parser SelectItem
-pFieldSelect = lexeme $
-  try (
-    do
-      alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
-      fld <- pField
-      cast' <- optionMaybe (string "::" *> many letter)
-      return (fld, toS <$> cast', alias, Nothing)
-  )
-  <|> do
-    s <- pStar
-    return ((s, Nothing), Nothing, Nothing, Nothing)
-
-pOperation :: Parser Operand -> Parser Operand -> Parser Operation
-pOperation parserVText parserVTextL = try ( string "not" *> pDelimiter *> (Operation True <$> pExpr)) <|> Operation False <$> pExpr
-  where
-    pExpr :: Parser (Operator, Operand)
-    pExpr =
-          ((,) <$> (toS <$> foldl1 (<|>) (try . ((<* pDelimiter) . string) . toS <$> M.keys notInOps)) <*> parserVText)
-      <|> ((,) <$> (toS <$> foldl1 (<|>) (try . ((<* pDelimiter) . string) . toS <$> M.keys inOps)) <*> parserVTextL)
-      <?> "operator (eq, gt, ...)"
-    inOps = M.filterWithKey (const . flip elem ["in", "notin"]) operators
-    notInOps = M.difference operators inOps
-
-pVText :: Parser Operand
-pVText = VText . toS <$> many anyChar
-
-pVTextL :: Parser Operand
-pVTextL =     VTextL <$> try (lexeme (char '(') *> pVTextLElement `sepBy1` char ',' <* lexeme (char ')'))
-          <|> VTextL <$> lexeme pVTextLElement `sepBy1` char ','
-
-pVTextLElement :: Parser Text
-pVTextLElement = try pQuotedValue <|> (toS <$> many (noneOf ",)"))
-
-pQuotedValue :: Parser Text
-pQuotedValue = toS <$> (char '"' *> many (noneOf "\"") <* char '"' <* notFollowedBy (noneOf ",)"))
-
-pDelimiter :: Parser Char
-pDelimiter = char '.' <?> "delimiter (.)"
-
-pOrder :: Parser [OrderTerm]
-pOrder = lexeme pOrderTerm `sepBy` char ','
-
-pOrderTerm :: Parser OrderTerm
-pOrderTerm =
-  try ( do
-    c <- pField
-    d <- optionMaybe (try $ pDelimiter *> (
-               try(string "asc" *> pure OrderAsc)
-           <|> try(string "desc" *> pure OrderDesc)
-         ))
-    nls <- optionMaybe (pDelimiter *> (
-                 try(string "nullslast" *> pure OrderNullsLast)
-             <|> try(string "nullsfirst" *> pure OrderNullsFirst)
-           ))
-    return $ OrderTerm c d nls
-  )
-  <|> OrderTerm <$> pField <*> pure Nothing <*> pure Nothing
-
-pLogicTree :: Parser LogicTree
-pLogicTree = Stmnt <$> try pLogicFilter
-             <|> Expr <$> pNot <*> pLogicOp <*> (lexeme (char '(') *> pLogicTree `sepBy1` lexeme (char ',') <* lexeme (char ')'))
-  where
-    pLogicFilter :: Parser Filter
-    pLogicFilter = Filter <$> pField <* pDelimiter <*> pOperation pLogicVText pLogicVTextL
-    pNot :: Parser Bool
-    pNot = try (string "not" *> pDelimiter *> pure True)
-           <|> pure False
-           <?> "negation operator (not)"
-    pLogicOp :: Parser LogicOperator
-    pLogicOp = try (string "and"  *> pure And)
-               <|> string "or" *> pure Or
-               <?> "logic operator (and, or)"
-
-pLogicVText :: Parser Operand
-pLogicVText = VText <$> (try pQuotedValue <|> try pPgArray <|> (toS <$> many (noneOf ",)")))
-  where
-    pPgArray :: Parser Text
-    pPgArray =  do
-      a <- string "{"
-      b <- many (noneOf "{}")
-      c <- string "}"
-      toS <$> pure (a ++ b ++ c)
-
-pLogicVTextL :: Parser Operand
-pLogicVTextL = VTextL <$> (lexeme (char '(') *> pVTextLElement `sepBy1` char ',' <* lexeme (char ')'))
-
-pLogicPath :: Parser (EmbedPath, Text)
-pLogicPath = do
-  path <- pFieldName `sepBy1` pDelimiter
-  let op = last path
-      notOp = "not." <> op
-  return (filter (/= "not") (init path), if "not" `elem` path then notOp else op)
-
-mapError :: Either ParseError a -> Either ApiRequestError a
-mapError = mapLeft translateError
-  where
-    translateError e =
-      ParseRequestError message details
-      where
-        message = show $ errorPos e
-        details = strip $ replace "\n" " " $ toS
-           $ showErrorMessages "or" "unknown parse error" "expecting" "unexpected" "end of input" (errorMessages e)

src/PostgREST/Query/QueryBuilder.hs

@@ -0,0 +1,181 @@
+{-# LANGUAGE DuplicateRecordFields #-}
+{-|
+Module      : PostgREST.Query.QueryBuilder
+Description : PostgREST SQL queries generating functions.
+
+This module provides functions to consume data types that
+represent database queries (e.g. ReadRequest, MutateRequest) and SqlFragment
+to produce SqlQuery type outputs.
+-}
+module PostgREST.Query.QueryBuilder
+  ( readRequestToQuery
+  , mutateRequestToQuery
+  , readRequestToCountQuery
+  , requestToCallProcQuery
+  , limitedQuery
+  ) where
+
+import qualified Data.ByteString.Char8           as BS
+import qualified Data.Set                        as S
+import qualified Hasql.DynamicStatements.Snippet as H
+
+import Data.Tree (Tree (..))
+
+import PostgREST.DbStructure.Identifiers  (FieldName,
+                                           QualifiedIdentifier (..))
+import PostgREST.DbStructure.Proc         (PgArg (..))
+import PostgREST.DbStructure.Relationship (Cardinality (..),
+                                           Relationship (..))
+import PostgREST.DbStructure.Table        (Table (..))
+import PostgREST.Request.ApiRequest       (PayloadJSON (..))
+import PostgREST.Request.Preferences      (PreferParameters (..),
+                                           PreferResolution (..))
+
+import PostgREST.Query.SqlFragment
+import PostgREST.Request.Types
+
+import Protolude
+
+readRequestToQuery :: ReadRequest -> H.Snippet
+readRequestToQuery (Node (Select colSelects mainQi tblAlias implJoins logicForest joinConditions_ ordts range, _) forest) =
+  "SELECT " <>
+  intercalateSnippet ", " ((pgFmtSelectItem qi <$> colSelects) ++ selects) <>
+  "FROM " <> H.sql (BS.intercalate ", " (tabl : implJs)) <> " " <>
+  intercalateSnippet " " joins <> " " <>
+  (if null logicForest && null joinConditions_ then mempty else "WHERE " <> intercalateSnippet " AND " (map (pgFmtLogicTree qi) logicForest ++ map pgFmtJoinCondition joinConditions_))
+  <> " " <>
+  (if null ordts then mempty else "ORDER BY " <> intercalateSnippet ", " (map (pgFmtOrderTerm qi) ordts)) <> " " <>
+  limitOffsetF range
+  where
+    implJs = fromQi <$> implJoins
+    tabl = fromQi mainQi <> maybe mempty (\a -> " AS " <> pgFmtIdent a) tblAlias
+    qi = maybe mainQi (QualifiedIdentifier mempty) tblAlias
+    (joins, selects) = foldr getJoinsSelects ([],[]) forest
+
+getJoinsSelects :: ReadRequest -> ([H.Snippet], [H.Snippet]) -> ([H.Snippet], [H.Snippet])
+getJoinsSelects rr@(Node (_, (name, Just Relationship{relCardinality=card,relTable=Table{tableName=table}}, alias, _, _)) _) (j,s) =
+  let subquery = readRequestToQuery rr in
+  case card of
+    M2O _ ->
+      let aliasOrName = fromMaybe name alias
+          localTableName = pgFmtIdent $ table <> "_" <> aliasOrName
+          sel = H.sql ("row_to_json(" <> localTableName <> ".*) AS " <> pgFmtIdent aliasOrName)
+          joi = " LEFT JOIN LATERAL( " <> subquery <> " ) AS " <> H.sql localTableName <> " ON TRUE " in
+      (joi:j,sel:s)
+    _ ->
+      let sel = "COALESCE (("
+             <> "SELECT json_agg(" <> H.sql (pgFmtIdent table) <> ".*) "
+             <> "FROM (" <> subquery <> ") " <> H.sql (pgFmtIdent table) <> " "
+             <> "), '[]') AS " <> H.sql (pgFmtIdent (fromMaybe name alias)) in
+      (j,sel:s)
+getJoinsSelects (Node (_, (_, Nothing, _, _, _)) _) _ = ([], [])
+
+mutateRequestToQuery :: MutateRequest -> H.Snippet
+mutateRequestToQuery (Insert mainQi iCols body onConflct putConditions returnings) =
+  "WITH " <> normalizedBody body <> " " <>
+  "INSERT INTO " <> H.sql (fromQi mainQi) <> H.sql (if S.null iCols then " " else "(" <> cols <> ") ") <>
+  "SELECT " <> H.sql cols <> " " <>
+  H.sql ("FROM json_populate_recordset (null::" <> fromQi mainQi <> ", " <> selectBody <> ") _ ") <>
+  -- Only used for PUT
+  (if null putConditions then mempty else "WHERE " <> intercalateSnippet " AND " (pgFmtLogicTree (QualifiedIdentifier mempty "_") <$> putConditions)) <>
+  H.sql (BS.unwords [
+    maybe "" (\(oncDo, oncCols) ->
+      if null oncCols then
+        mempty
+      else
+        "ON CONFLICT(" <> BS.intercalate ", " (pgFmtIdent <$> oncCols) <> ") " <> case oncDo of
+        IgnoreDuplicates ->
+          "DO NOTHING"
+        MergeDuplicates  ->
+          if S.null iCols
+             then "DO NOTHING"
+             else "DO UPDATE SET " <> BS.intercalate ", " (pgFmtIdent <> const " = EXCLUDED." <> pgFmtIdent <$> S.toList iCols)
+      ) onConflct,
+    returningF mainQi returnings
+    ])
+  where
+    cols = BS.intercalate ", " $ pgFmtIdent <$> S.toList iCols
+mutateRequestToQuery (Update mainQi uCols body logicForest returnings) =
+  if S.null uCols
+    -- if there are no columns we cannot do UPDATE table SET {empty}, it'd be invalid syntax
+    -- selecting an empty resultset from mainQi gives us the column names to prevent errors when using &select=
+    -- the select has to be based on "returnings" to make computed overloaded functions not throw
+    then H.sql ("SELECT " <> emptyBodyReturnedColumns <> " FROM " <> fromQi mainQi <> " WHERE false")
+    else
+      "WITH " <> normalizedBody body <> " " <>
+      "UPDATE " <> H.sql (fromQi mainQi) <> " SET " <> H.sql cols <> " " <>
+      "FROM (SELECT * FROM json_populate_recordset (null::" <> H.sql (fromQi mainQi) <> " , " <> H.sql selectBody <> " )) _ " <>
+      (if null logicForest then mempty else "WHERE " <> intercalateSnippet " AND " (pgFmtLogicTree mainQi <$> logicForest)) <> " " <>
+      H.sql (returningF mainQi returnings)
+  where
+    cols = BS.intercalate ", " (pgFmtIdent <> const " = _." <> pgFmtIdent <$> S.toList uCols)
+    emptyBodyReturnedColumns :: SqlFragment
+    emptyBodyReturnedColumns
+      | null returnings = "NULL"
+      | otherwise       = BS.intercalate ", " (pgFmtColumn (QualifiedIdentifier mempty $ qiName mainQi) <$> returnings)
+mutateRequestToQuery (Delete mainQi logicForest returnings) =
+  "DELETE FROM " <> H.sql (fromQi mainQi) <> " " <>
+  (if null logicForest then mempty else "WHERE " <> intercalateSnippet " AND " (map (pgFmtLogicTree mainQi) logicForest)) <> " " <>
+  H.sql (returningF mainQi returnings)
+
+requestToCallProcQuery :: QualifiedIdentifier -> [PgArg] -> Maybe PayloadJSON -> Bool -> Maybe PreferParameters -> [FieldName] -> H.Snippet
+requestToCallProcQuery qi pgArgs pj returnsScalar preferParams returnings =
+  argsCTE <> sourceBody
+  where
+    body = pjRaw <$> pj
+    paramsAsSingleObject    = preferParams == Just SingleObject
+    paramsAsMultipleObjects = preferParams == Just MultipleObjects
+
+    (argsCTE, args)
+      | null pgArgs = (mempty, mempty)
+      | paramsAsSingleObject = ("WITH pgrst_args AS (SELECT NULL)", jsonPlaceHolder body)
+      | otherwise = (
+          "WITH " <> normalizedBody body <> ", " <>
+          H.sql (
+            BS.unwords [
+            "pgrst_args AS (",
+              "SELECT * FROM json_to_recordset(" <> selectBody <> ") AS _(" <> fmtArgs (const mempty) (\a -> " " <> encodeUtf8 (pgaType a)) <> ")",
+            ")"])
+         , H.sql $ if paramsAsMultipleObjects
+             then fmtArgs varadicPrefix (\a -> " := pgrst_args." <> pgFmtIdent (pgaName a))
+             else fmtArgs varadicPrefix (\a -> " := (SELECT " <> pgFmtIdent (pgaName a) <> " FROM pgrst_args LIMIT 1)")
+        )
+
+    fmtArgs :: (PgArg -> SqlFragment) -> (PgArg -> SqlFragment) -> SqlFragment
+    fmtArgs argFragPre argFragSuf = BS.intercalate ", " ((\a -> argFragPre a <> pgFmtIdent (pgaName a) <> argFragSuf a) <$> pgArgs)
+
+    varadicPrefix :: PgArg -> SqlFragment
+    varadicPrefix a = if pgaVar a then "VARIADIC " else mempty
+
+    sourceBody :: H.Snippet
+    sourceBody
+      | paramsAsMultipleObjects =
+          if returnsScalar
+            then "SELECT " <> callIt <> " AS pgrst_scalar FROM pgrst_args"
+            else "SELECT pgrst_lat_args.* FROM pgrst_args, " <>
+                 "LATERAL ( SELECT " <> returnedColumns <> " FROM " <> callIt <> " ) pgrst_lat_args"
+      | otherwise =
+          if returnsScalar
+            then "SELECT " <> callIt <> " AS pgrst_scalar"
+            else "SELECT " <> returnedColumns <> " FROM " <> callIt
+
+    callIt :: H.Snippet
+    callIt = H.sql (fromQi qi) <> "(" <> args <> ")"
+
+    returnedColumns :: H.Snippet
+    returnedColumns
+      | null returnings = "*"
+      | otherwise       = H.sql $ BS.intercalate ", " (pgFmtColumn (QualifiedIdentifier mempty $ qiName qi) <$> returnings)
+
+
+-- | SQL query meant for COUNTing the root node of the Tree.
+-- It only takes WHERE into account and doesn't include LIMIT/OFFSET because it would reduce the COUNT.
+-- SELECT 1 is done instead of SELECT * to prevent doing expensive operations(like functions based on the columns)
+-- inside the FROM target.
+readRequestToCountQuery :: ReadRequest -> H.Snippet
+readRequestToCountQuery (Node (Select{from=qi, where_=logicForest}, _) _) =
+ "SELECT 1 " <> "FROM " <> H.sql (fromQi qi) <> " " <>
+ if null logicForest then mempty else "WHERE " <> intercalateSnippet " AND " (map (pgFmtLogicTree qi) logicForest)
+
+limitedQuery :: H.Snippet -> Maybe Integer -> H.Snippet
+limitedQuery query maxRows = query <> H.sql (maybe mempty (\x -> " LIMIT " <> BS.pack (show x)) maxRows)

src/PostgREST/Query/SqlFragment.hs

@@ -0,0 +1,322 @@
+{-# LANGUAGE LambdaCase  #-}
+{-# LANGUAGE QuasiQuotes #-}
+{-|
+Module      : PostgREST.Query.SqlFragment
+Description : Helper functions for PostgREST.QueryBuilder.
+
+Any function that outputs a SqlFragment should be in this module.
+-}
+module PostgREST.Query.SqlFragment
+  ( noLocationF
+  , SqlFragment
+  , asBinaryF
+  , asCsvF
+  , asJsonF
+  , asJsonSingleF
+  , countF
+  , fromQi
+  , ftsOperators
+  , jsonPlaceHolder
+  , limitOffsetF
+  , locationF
+  , normalizedBody
+  , operators
+  , pgFmtColumn
+  , pgFmtIdent
+  , pgFmtJoinCondition
+  , pgFmtLogicTree
+  , pgFmtOrderTerm
+  , pgFmtSelectItem
+  , responseHeadersF
+  , responseStatusF
+  , returningF
+  , selectBody
+  , sourceCTEName
+  , unknownEncoder
+  , intercalateSnippet
+  ) where
+
+import qualified Data.ByteString.Char8           as BS
+import qualified Data.ByteString.Lazy            as BL
+import qualified Data.HashMap.Strict             as HM
+import qualified Data.Text                       as T
+import qualified Hasql.DynamicStatements.Snippet as H
+import qualified Hasql.Encoders                  as HE
+
+import Data.Foldable                 (foldr1)
+import Text.InterpolatedString.Perl6 (qc)
+
+import PostgREST.Config.PgVersion        (PgVersion, pgVersion96)
+import PostgREST.DbStructure.Identifiers (FieldName,
+                                          QualifiedIdentifier (..))
+import PostgREST.RangeQuery              (NonnegRange, allRange,
+                                          rangeLimit, rangeOffset)
+import PostgREST.Request.Types           (Alias, Field, Filter (..),
+                                          JoinCondition (..),
+                                          JsonOperand (..),
+                                          JsonOperation (..),
+                                          JsonPath, LogicTree (..),
+                                          OpExpr (..), Operation (..),
+                                          OrderTerm (..), SelectItem)
+
+import Protolude      hiding (cast, toS)
+import Protolude.Conv (toS)
+
+
+-- | A part of a SQL query that cannot be executed independently
+type SqlFragment = ByteString
+
+noLocationF :: SqlFragment
+noLocationF = "array[]::text[]"
+
+sourceCTEName :: SqlFragment
+sourceCTEName = "pgrst_source"
+
+operators :: HM.HashMap Text SqlFragment
+operators = HM.union (HM.fromList [
+  ("eq", "="),
+  ("gte", ">="),
+  ("gt", ">"),
+  ("lte", "<="),
+  ("lt", "<"),
+  ("neq", "<>"),
+  ("like", "LIKE"),
+  ("ilike", "ILIKE"),
+  ("in", "IN"),
+  ("is", "IS"),
+  ("cs", "@>"),
+  ("cd", "<@"),
+  ("ov", "&&"),
+  ("sl", "<<"),
+  ("sr", ">>"),
+  ("nxr", "&<"),
+  ("nxl", "&>"),
+  ("adj", "-|-")]) ftsOperators
+
+ftsOperators :: HM.HashMap Text SqlFragment
+ftsOperators = HM.fromList [
+  ("fts", "@@ to_tsquery"),
+  ("plfts", "@@ plainto_tsquery"),
+  ("phfts", "@@ phraseto_tsquery"),
+  ("wfts", "@@ websearch_to_tsquery")
+  ]
+
+-- |
+-- These CTEs convert a json object into a json array, this way we can use json_populate_recordset for all json payloads
+-- Otherwise we'd have to use json_populate_record for json objects and json_populate_recordset for json arrays
+-- We do this in SQL to avoid processing the JSON in application code
+normalizedBody :: Maybe BL.ByteString -> H.Snippet
+normalizedBody body =
+  "pgrst_payload AS (SELECT " <> jsonPlaceHolder body <> " AS json_data), " <>
+  H.sql (BS.unwords [
+    "pgrst_body AS (",
+      "SELECT",
+        "CASE WHEN json_typeof(json_data) = 'array'",
+          "THEN json_data",
+          "ELSE json_build_array(json_data)",
+        "END AS val",
+      "FROM pgrst_payload)"])
+
+-- | Equivalent to "$1::json"
+-- | TODO: At this stage there shouldn't be a Maybe since ApiRequest should ensure that an INSERT/UPDATE has a body
+jsonPlaceHolder :: Maybe BL.ByteString -> H.Snippet
+jsonPlaceHolder body =
+  H.encoderAndParam (HE.nullable HE.unknown) (toS <$> body) <> "::json"
+
+selectBody :: SqlFragment
+selectBody = "(SELECT val FROM pgrst_body)"
+
+pgFmtLit :: Text -> SqlFragment
+pgFmtLit x =
+ let trimmed = trimNullChars x
+     escaped = "'" <> T.replace "'" "''" trimmed <> "'"
+     slashed = T.replace "\\" "\\\\" escaped in
+ encodeUtf8 $ if "\\" `T.isInfixOf` escaped
+   then "E" <> slashed
+   else slashed
+
+-- TODO: refactor by following https://github.com/PostgREST/postgrest/pull/1631#issuecomment-711070833
+pgFmtIdent :: Text -> SqlFragment
+pgFmtIdent x = encodeUtf8 $ "\"" <> T.replace "\"" "\"\"" (trimNullChars x) <> "\""
+
+trimNullChars :: Text -> Text
+trimNullChars = T.takeWhile (/= '\x0')
+
+asCsvF :: SqlFragment
+asCsvF = asCsvHeaderF <> " || '\n' || " <> asCsvBodyF
+  where
+    asCsvHeaderF =
+      "(SELECT coalesce(string_agg(a.k, ','), '')" <>
+      "  FROM (" <>
+      "    SELECT json_object_keys(r)::text as k" <>
+      "    FROM ( " <>
+      "      SELECT row_to_json(hh) as r from " <> sourceCTEName <> " as hh limit 1" <>
+      "    ) s" <>
+      "  ) a" <>
+      ")"
+    asCsvBodyF = "coalesce(string_agg(substring(_postgrest_t::text, 2, length(_postgrest_t::text) - 2), '\n'), '')"
+
+asJsonF :: Bool -> SqlFragment
+asJsonF returnsScalar
+  | returnsScalar = "coalesce(json_agg(_postgrest_t.pgrst_scalar), '[]')::character varying"
+  | otherwise     = "coalesce(json_agg(_postgrest_t), '[]')::character varying"
+
+asJsonSingleF :: Bool -> SqlFragment --TODO! unsafe when the query actually returns multiple rows, used only on inserting and returning single element
+asJsonSingleF returnsScalar
+  | returnsScalar = "coalesce(string_agg(to_json(_postgrest_t.pgrst_scalar)::text, ','), 'null')::character varying"
+  | otherwise     = "coalesce(string_agg(to_json(_postgrest_t)::text, ','), '')::character varying"
+
+asBinaryF :: FieldName -> SqlFragment
+asBinaryF fieldName = "coalesce(string_agg(_postgrest_t." <> pgFmtIdent fieldName <> ", ''), '')"
+
+locationF :: [Text] -> SqlFragment
+locationF pKeys = [qc|(
+  WITH data AS (SELECT row_to_json(_) AS row FROM {sourceCTEName} AS _ LIMIT 1)
+  SELECT array_agg(json_data.key || '=' || coalesce('eq.' || json_data.value, 'is.null'))
+  FROM data CROSS JOIN json_each_text(data.row) AS json_data
+  WHERE json_data.key IN ('{fmtPKeys}')
+)|]
+  where
+    fmtPKeys = T.intercalate "','" pKeys
+
+fromQi :: QualifiedIdentifier -> SqlFragment
+fromQi t = (if T.null s then mempty else pgFmtIdent s <> ".") <> pgFmtIdent n
+  where
+    n = qiName t
+    s = qiSchema t
+
+pgFmtColumn :: QualifiedIdentifier -> Text -> SqlFragment
+pgFmtColumn table "*" = fromQi table <> ".*"
+pgFmtColumn table c   = fromQi table <> "." <> pgFmtIdent c
+
+pgFmtField :: QualifiedIdentifier -> Field -> H.Snippet
+pgFmtField table (c, jp) = H.sql (pgFmtColumn table c) <> pgFmtJsonPath jp
+
+pgFmtSelectItem :: QualifiedIdentifier -> SelectItem -> H.Snippet
+pgFmtSelectItem table (f@(fName, jp), Nothing, alias, _) = pgFmtField table f <> H.sql (pgFmtAs fName jp alias)
+-- Ideally we'd quote the cast with "pgFmtIdent cast". However, that would invalidate common casts such as "int", "bigint", etc.
+-- Try doing: `select 1::"bigint"` - it'll err, using "int8" will work though. There's some parser magic that pg does that's invalidated when quoting.
+-- Not quoting should be fine, we validate the input on Parsers.
+pgFmtSelectItem table (f@(fName, jp), Just cast, alias, _) = "CAST (" <> pgFmtField table f <> " AS " <> H.sql (encodeUtf8 cast) <> " )" <> H.sql (pgFmtAs fName jp alias)
+
+pgFmtOrderTerm :: QualifiedIdentifier -> OrderTerm -> H.Snippet
+pgFmtOrderTerm qi ot =
+  pgFmtField qi (otTerm ot) <> " " <>
+  H.sql (BS.unwords [
+    BS.pack $ maybe mempty show $ otDirection ot,
+    BS.pack $ maybe mempty show $ otNullOrder ot])
+
+pgFmtFilter :: QualifiedIdentifier -> Filter -> H.Snippet
+pgFmtFilter table (Filter fld (OpExpr hasNot oper)) = notOp <> " " <> case oper of
+   Op op val  -> pgFmtFieldOp op <> " " <> case op of
+     "like"  -> unknownLiteral (T.map star val)
+     "ilike" -> unknownLiteral (T.map star val)
+     "is"    -> isAllowed val
+     _       -> unknownLiteral val
+
+   -- We don't use "IN", we use "= ANY". IN has the following disadvantages:
+   -- + No way to use an empty value on IN: "col IN ()" is invalid syntax. With ANY we can do "= ANY('{}')"
+   -- + Can invalidate prepared statements: multiple parameters on an IN($1, $2, $3) will lead to using different prepared statements and not take advantage of caching.
+   In vals -> pgFmtField table fld <> " " <>
+    case vals of
+      [""] -> "= ANY('{}') "
+      -- Here we build the pg array, e.g '{"Hebdon, John","Other","Another"}', manually. We quote the values to prevent the "," being treated as an element separator.
+      -- TODO: Ideally this would be done on Hasql with an encoder, but the "array unknown" is not working(Hasql doesn't pass any value).
+      _    -> "= ANY (" <> unknownLiteral ("{" <> T.intercalate "," ((\x -> "\"" <> x <> "\"") <$> vals) <> "}") <> ")"
+
+   Fts op lang val ->
+     pgFmtFieldOp op <> "(" <> ftsLang lang <> unknownLiteral val <> ") "
+ where
+   ftsLang = maybe mempty (\l -> unknownLiteral l <> ", ")
+   pgFmtFieldOp op = pgFmtField table fld <> " " <> sqlOperator op
+   sqlOperator o = H.sql $ HM.lookupDefault "=" o operators
+   notOp = if hasNot then "NOT" else mempty
+   star c = if c == '*' then '%' else c
+   -- IS cannot be prepared. `PREPARE boolplan AS SELECT * FROM projects where id IS $1` will give a syntax error.
+   -- The above can be fixed by using `PREPARE boolplan AS SELECT * FROM projects where id IS NOT DISTINCT FROM $1;`
+   -- However that would not accept the TRUE/FALSE/NULL keywords. See: https://stackoverflow.com/questions/6133525/proper-way-to-set-preparedstatement-parameter-to-null-under-postgres.
+   isAllowed :: Text -> H.Snippet
+   isAllowed v = H.sql $ maybe
+     (pgFmtLit v <> "::unknown") encodeUtf8
+     (find ((==) . T.toLower $ v) ["null","true","false"])
+
+pgFmtJoinCondition :: JoinCondition -> H.Snippet
+pgFmtJoinCondition (JoinCondition (qi1, col1) (qi2, col2)) =
+  H.sql $ pgFmtColumn qi1 col1 <> " = " <> pgFmtColumn qi2 col2
+
+pgFmtLogicTree :: QualifiedIdentifier -> LogicTree -> H.Snippet
+pgFmtLogicTree qi (Expr hasNot op forest) = H.sql notOp <> " (" <> intercalateSnippet (" " <> BS.pack (show op) <> " ") (pgFmtLogicTree qi <$> forest) <> ")"
+  where notOp =  if hasNot then "NOT" else mempty
+pgFmtLogicTree qi (Stmnt flt) = pgFmtFilter qi flt
+
+pgFmtJsonPath :: JsonPath -> H.Snippet
+pgFmtJsonPath = \case
+  []             -> mempty
+  (JArrow x:xs)  -> "->" <> pgFmtJsonOperand x <> pgFmtJsonPath xs
+  (J2Arrow x:xs) -> "->>" <> pgFmtJsonOperand x <> pgFmtJsonPath xs
+  where
+    pgFmtJsonOperand (JKey k) = unknownLiteral k
+    pgFmtJsonOperand (JIdx i) = unknownLiteral i <> "::int"
+
+pgFmtAs :: FieldName -> JsonPath -> Maybe Alias -> SqlFragment
+pgFmtAs _ [] Nothing = mempty
+pgFmtAs fName jp Nothing = case jOp <$> lastMay jp of
+  Just (JKey key) -> " AS " <> pgFmtIdent key
+  Just (JIdx _)   -> " AS " <> pgFmtIdent (fromMaybe fName lastKey)
+    -- We get the lastKey because on:
+    -- `select=data->1->mycol->>2`, we need to show the result as [ {"mycol": ..}, {"mycol": ..} ]
+    -- `select=data->3`, we need to show the result as [ {"data": ..}, {"data": ..} ]
+    where lastKey = jVal <$> find (\case JKey{} -> True; _ -> False) (jOp <$> reverse jp)
+  Nothing -> mempty
+pgFmtAs _ _ (Just alias) = " AS " <> pgFmtIdent alias
+
+countF :: H.Snippet -> Bool -> (H.Snippet, SqlFragment)
+countF countQuery shouldCount =
+  if shouldCount
+    then (
+        ", pgrst_source_count AS (" <> countQuery <> ")"
+      , "(SELECT pg_catalog.count(*) FROM pgrst_source_count)" )
+    else (
+        mempty
+      , "null::bigint")
+
+returningF :: QualifiedIdentifier -> [FieldName] -> SqlFragment
+returningF qi returnings =
+  if null returnings
+    then "RETURNING 1" -- For mutation cases where there's no ?select, we return 1 to know how many rows were modified
+    else "RETURNING " <> BS.intercalate ", " (pgFmtColumn qi <$> returnings)
+
+limitOffsetF :: NonnegRange -> H.Snippet
+limitOffsetF range =
+  if range == allRange then mempty else "LIMIT " <> limit <> " OFFSET " <> offset
+  where
+    limit = maybe "ALL" (\l -> unknownEncoder (BS.pack $ show l)) $ rangeLimit range
+    offset = unknownEncoder (BS.pack . show $ rangeOffset range)
+
+responseHeadersF :: PgVersion -> SqlFragment
+responseHeadersF pgVer =
+  if pgVer >= pgVersion96
+    then currentSettingF "response.headers"
+    else "null"
+
+responseStatusF :: PgVersion -> SqlFragment
+responseStatusF pgVer =
+  if pgVer >= pgVersion96
+    then currentSettingF "response.status"
+    else "null"
+
+currentSettingF :: Text -> SqlFragment
+currentSettingF setting =
+  -- nullif is used because of https://gist.github.com/steve-chavez/8d7033ea5655096903f3b52f8ed09a15
+  "nullif(current_setting(" <> pgFmtLit setting <> ", true), '')"
+
+-- Hasql Snippet utilities
+unknownEncoder :: ByteString -> H.Snippet
+unknownEncoder = H.encoderAndParam (HE.nonNullable HE.unknown)
+
+unknownLiteral :: Text -> H.Snippet
+unknownLiteral = unknownEncoder . encodeUtf8
+
+intercalateSnippet :: ByteString -> [H.Snippet] -> H.Snippet
+intercalateSnippet _ [] = mempty
+intercalateSnippet frag snippets = foldr1 (\a b -> a <> H.sql frag <> b) snippets

src/PostgREST/Query/Statements.hs

@@ -0,0 +1,204 @@
+{-|
+Module      : PostgREST.Query.Statements
+Description : PostgREST single SQL statements.
+
+This module constructs single SQL statements that can be parametrized and prepared.
+
+- It consumes the SqlQuery types generated by the QueryBuilder module.
+- It generates the body format and some headers of the final HTTP response.
+
+TODO: Currently, createReadStatement is not using prepared statements. See https://github.com/PostgREST/postgrest/issues/718.
+-}
+module PostgREST.Query.Statements
+  ( createWriteStatement
+  , createReadStatement
+  , callProcStatement
+  , createExplainStatement
+  ) where
+
+import qualified Data.Aeson                        as JSON
+import qualified Data.Aeson.Lens                   as L
+import qualified Data.ByteString.Char8             as BS
+import qualified Hasql.Decoders                    as HD
+import qualified Hasql.DynamicStatements.Snippet   as H
+import qualified Hasql.DynamicStatements.Statement as H
+import qualified Hasql.Statement                   as H
+
+import Control.Lens              ((^?))
+import Data.Maybe                (fromJust)
+import Data.Text.Read            (decimal)
+import Network.HTTP.Types.Status (Status)
+
+import PostgREST.Config.PgVersion (PgVersion)
+import PostgREST.Error            (Error (..))
+import PostgREST.GucHeader        (GucHeader)
+
+import PostgREST.DbStructure.Identifiers (FieldName)
+import PostgREST.Query.SqlFragment
+import PostgREST.Request.Preferences
+
+import Protolude      hiding (toS)
+import Protolude.Conv (toS)
+
+{-| The generic query result format used by API responses. The location header
+    is represented as a list of strings containing variable bindings like
+    @"k1=eq.42"@, or the empty list if there is no location header.
+-}
+type ResultsWithCount = (Maybe Int64, Int64, [BS.ByteString], BS.ByteString, Either Error [GucHeader], Either Error (Maybe Status))
+
+createWriteStatement :: H.Snippet -> H.Snippet -> Bool -> Bool -> Bool ->
+                        PreferRepresentation -> [Text] -> PgVersion -> Bool ->
+                        H.Statement () ResultsWithCount
+createWriteStatement selectQuery mutateQuery wantSingle isInsert asCsv rep pKeys pgVer =
+  H.dynamicallyParameterized snippet decodeStandard
+ where
+  snippet =
+    "WITH " <> H.sql sourceCTEName <> " AS (" <> mutateQuery <> ") " <>
+    H.sql (
+    "SELECT " <>
+      "'' AS total_result_set, " <>
+      "pg_catalog.count(_postgrest_t) AS page_total, " <>
+      locF <> " AS header, " <>
+      bodyF <> " AS body, " <>
+      responseHeadersF pgVer <> " AS response_headers, " <>
+      responseStatusF pgVer  <> " AS response_status "
+    ) <>
+    "FROM (" <> selectF <> ") _postgrest_t"
+
+  locF =
+    if isInsert && rep `elem` [Full, HeadersOnly]
+      then BS.unwords [
+        "CASE WHEN pg_catalog.count(_postgrest_t) = 1",
+          "THEN coalesce(" <> locationF pKeys <> ", " <> noLocationF <> ")",
+          "ELSE " <> noLocationF,
+        "END"]
+      else noLocationF
+
+  bodyF
+    | rep `elem` [None, HeadersOnly] = "''"
+    | asCsv = asCsvF
+    | wantSingle = asJsonSingleF False
+    | otherwise = asJsonF False
+
+  selectF
+    -- prevent using any of the column names in ?select= when no response is returned from the CTE
+    | rep `elem` [None, HeadersOnly] = H.sql ("SELECT * FROM " <> sourceCTEName)
+    | otherwise                      = selectQuery
+
+  decodeStandard :: HD.Result ResultsWithCount
+  decodeStandard =
+   fromMaybe (Nothing, 0, [], mempty, Right [], Right Nothing) <$> HD.rowMaybe standardRow
+
+createReadStatement :: H.Snippet -> H.Snippet -> Bool -> Bool -> Bool -> Maybe FieldName -> PgVersion -> Bool ->
+                       H.Statement () ResultsWithCount
+createReadStatement selectQuery countQuery isSingle countTotal asCsv binaryField pgVer =
+  H.dynamicallyParameterized snippet decodeStandard
+ where
+  snippet =
+    "WITH " <>
+    H.sql sourceCTEName <> " AS ( " <> selectQuery <> " ) " <>
+    countCTEF <> " " <>
+    H.sql ("SELECT " <>
+      countResultF <> " AS total_result_set, " <>
+      "pg_catalog.count(_postgrest_t) AS page_total, " <>
+      noLocationF <> " AS header, " <>
+      bodyF <> " AS body, " <>
+      responseHeadersF pgVer <> " AS response_headers, " <>
+      responseStatusF pgVer <> " AS response_status " <>
+    "FROM ( SELECT * FROM " <> sourceCTEName <> " ) _postgrest_t")
+
+  (countCTEF, countResultF) = countF countQuery countTotal
+
+  bodyF
+    | asCsv = asCsvF
+    | isSingle = asJsonSingleF False
+    | isJust binaryField = asBinaryF $ fromJust binaryField
+    | otherwise = asJsonF False
+
+  decodeStandard :: HD.Result ResultsWithCount
+  decodeStandard =
+    HD.singleRow standardRow
+
+{-| Read and Write api requests use a similar response format which includes
+    various record counts and possible location header. This is the decoder
+    for that common type of query.
+-}
+standardRow :: HD.Row ResultsWithCount
+standardRow = (,,,,,) <$> nullableColumn HD.int8 <*> column HD.int8
+                      <*> arrayColumn HD.bytea <*> column HD.bytea
+                      <*> (fromMaybe (Right []) <$> nullableColumn decodeGucHeaders)
+                      <*> (fromMaybe (Right Nothing) <$> nullableColumn decodeGucStatus)
+
+type ProcResults = (Maybe Int64, Int64, ByteString, Either Error [GucHeader], Either Error (Maybe Status))
+
+callProcStatement :: Bool -> Bool -> H.Snippet -> H.Snippet -> H.Snippet -> Bool ->
+                     Bool -> Bool -> Bool -> Maybe FieldName -> PgVersion -> Bool ->
+                     H.Statement () ProcResults
+callProcStatement returnsScalar returnsSingle callProcQuery selectQuery countQuery countTotal asSingle asCsv multObjects binaryField pgVer =
+  H.dynamicallyParameterized snippet decodeProc
+  where
+    snippet =
+      "WITH " <> H.sql sourceCTEName <> " AS (" <> callProcQuery <> ") " <>
+      countCTEF <>
+      H.sql (
+      "SELECT " <>
+        countResultF <> " AS total_result_set, " <>
+        "pg_catalog.count(_postgrest_t) AS page_total, " <>
+        bodyF <> " AS body, " <>
+        responseHeadersF pgVer <> " AS response_headers, " <>
+        responseStatusF pgVer <> " AS response_status ") <>
+      "FROM (" <> selectQuery <> ") _postgrest_t"
+
+    (countCTEF, countResultF) = countF countQuery countTotal
+
+    bodyF
+     | asSingle           = asJsonSingleF returnsScalar
+     | asCsv              = asCsvF
+     | isJust binaryField = asBinaryF $ fromJust binaryField
+     | returnsSingle
+       && not multObjects = asJsonSingleF returnsScalar
+     | otherwise          = asJsonF returnsScalar
+
+    decodeProc :: HD.Result ProcResults
+    decodeProc =
+      fromMaybe (Just 0, 0, mempty, defGucHeaders, defGucStatus) <$> HD.rowMaybe procRow
+      where
+        defGucHeaders = Right []
+        defGucStatus  = Right Nothing
+        procRow = (,,,,) <$> nullableColumn HD.int8 <*> column HD.int8
+                         <*> column HD.bytea
+                         <*> (fromMaybe defGucHeaders <$> nullableColumn decodeGucHeaders)
+                         <*> (fromMaybe defGucStatus <$> nullableColumn decodeGucStatus)
+
+createExplainStatement :: H.Snippet -> Bool -> H.Statement () (Maybe Int64)
+createExplainStatement countQuery =
+  H.dynamicallyParameterized snippet decodeExplain
+  where
+    snippet = "EXPLAIN (FORMAT JSON) " <> countQuery
+    -- |
+    -- An `EXPLAIN (FORMAT JSON) select * from items;` output looks like this:
+    -- [{
+    --   "Plan": {
+    --     "Node Type": "Seq Scan", "Parallel Aware": false, "Relation Name": "items",
+    --     "Alias": "items", "Startup Cost": 0.00, "Total Cost": 32.60,
+    --     "Plan Rows": 2260,"Plan Width": 8} }]
+    -- We only obtain the Plan Rows here.
+    decodeExplain :: HD.Result (Maybe Int64)
+    decodeExplain =
+      let row = HD.singleRow $ column HD.bytea in
+      (^? L.nth 0 . L.key "Plan" .  L.key "Plan Rows" . L._Integral) <$> row
+
+decodeGucHeaders :: HD.Value (Either Error [GucHeader])
+decodeGucHeaders = first (const GucHeadersError) . JSON.eitherDecode . toS <$> HD.bytea
+
+decodeGucStatus :: HD.Value (Either Error (Maybe Status))
+decodeGucStatus = first (const GucStatusError) . fmap (Just . toEnum . fst) . decimal <$> HD.text
+
+column :: HD.Value a -> HD.Row a
+column = HD.column . HD.nonNullable
+
+nullableColumn :: HD.Value a -> HD.Row (Maybe a)
+nullableColumn = HD.column . HD.nullable
+
+arrayColumn :: HD.Value a -> HD.Row [a]
+arrayColumn = column . HD.listArray . HD.nonNullable

src/PostgREST/QueryBuilder.hs

@@ -1,472 +0,0 @@
-{-# LANGUAGE FlexibleInstances    #-}
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-{-|
-Module      : PostgREST.QueryBuilder
-Description : PostgREST SQL generating functions.
-
-This module provides functions to consume data types that
-represent database objects (e.g. Relation, Schema, SqlQuery)
-and produces SQL Statements.
-
-Any function that outputs a SQL fragment should be in this module.
--}
-module PostgREST.QueryBuilder (
-    callProc
-  , createReadStatement
-  , createWriteStatement
-  , getJoinFilters
-  , pgFmtIdent
-  , pgFmtLit
-  , requestToQuery
-  , requestToCountQuery
-  , sourceCTEName
-  , unquoted
-  , ResultsWithCount
-  , pgFmtEnvVar
-  ) where
-
-import qualified Hasql.Query             as H
-import qualified Hasql.Encoders          as HE
-import qualified Hasql.Decoders          as HD
-
-import qualified Data.Aeson              as JSON
-
-import           PostgREST.RangeQuery    (NonnegRange, rangeLimit, rangeOffset, allRange)
-import           Data.Functor.Contravariant (contramap)
-import qualified Data.HashMap.Strict     as HM
-import           Data.Maybe
-import           Data.Text               (intercalate, unwords, replace, isInfixOf, toLower)
-import qualified Data.Text as T          (map, takeWhile, null)
-import qualified Data.Text.Encoding as T
-import           Data.Tree               (Tree(..))
-import qualified Data.Vector as V
-import           PostgREST.Types
-import           Text.InterpolatedString.Perl6 (qc)
-import qualified Data.ByteString.Char8   as BS
-import           Data.Scientific         ( FPFormat (..)
-                                         , formatScientific
-                                         , isInteger
-                                         )
-import           Protolude hiding        (from, intercalate, ord, cast, replace)
-import           PostgREST.ApiRequest    (PreferRepresentation (..))
-
-{-| The generic query result format used by API responses. The location header
-    is represented as a list of strings containing variable bindings like
-    @"k1=eq.42"@, or the empty list if there is no location header.
--}
-type ResultsWithCount = (Maybe Int64, Int64, [BS.ByteString], BS.ByteString)
-
-standardRow :: HD.Row ResultsWithCount
-standardRow = (,,,) <$> HD.nullableValue HD.int8 <*> HD.value HD.int8
-                    <*> HD.value header <*> HD.value HD.bytea
-  where
-    header = HD.array $ HD.arrayDimension replicateM $ HD.arrayValue HD.bytea
-
-noLocationF :: Text
-noLocationF = "array[]::text[]"
-
-{-| Read and Write api requests use a similar response format which includes
-    various record counts and possible location header. This is the decoder
-    for that common type of query.
--}
-decodeStandard :: HD.Result ResultsWithCount
-decodeStandard =
-  HD.singleRow standardRow
-
-decodeStandardMay :: HD.Result (Maybe ResultsWithCount)
-decodeStandardMay =
-  HD.maybeRow standardRow
-
-{-| JSON and CSV payloads from the client are given to us as
-    PayloadJSON (objects who all have the same keys),
-    and we turn this into an old fasioned JSON array
--}
-encodeUniformObjs :: HE.Params PayloadJSON
-encodeUniformObjs =
-  contramap (JSON.Array . V.map JSON.Object . unPayloadJSON) (HE.value HE.json)
-
-createReadStatement :: SqlQuery -> SqlQuery -> Bool -> Bool -> Bool -> Maybe FieldName ->
-                       H.Query () ResultsWithCount
-createReadStatement selectQuery countQuery isSingle countTotal asCsv binaryField =
-  unicodeStatement sql HE.unit decodeStandard False
- where
-  sql = [qc|
-      WITH {sourceCTEName} AS ({selectQuery}) SELECT {cols}
-      FROM ( SELECT * FROM {sourceCTEName}) _postgrest_t |]
-  countResultF = if countTotal then "("<>countQuery<>")" else "null"
-  cols = intercalate ", " [
-      countResultF <> " AS total_result_set",
-      "pg_catalog.count(_postgrest_t) AS page_total",
-      noLocationF <> " AS header",
-      bodyF <> " AS body"
-    ]
-  bodyF
-    | asCsv = asCsvF
-    | isSingle = asJsonSingleF
-    | isJust binaryField = asBinaryF $ fromJust binaryField
-    | otherwise = asJsonF
-
-createWriteStatement :: SqlQuery -> SqlQuery -> Bool -> Bool -> Bool ->
-                        PreferRepresentation -> [Text] ->
-                        H.Query PayloadJSON (Maybe ResultsWithCount)
-createWriteStatement selectQuery mutateQuery wantSingle wantHdrs asCsv rep pKeys =
-  unicodeStatement sql encodeUniformObjs decodeStandardMay True
-
- where
-  sql = case rep of
-    None -> [qc|
-      WITH {sourceCTEName} AS ({mutateQuery})
-      SELECT '', 0, {noLocationF}, '' |]
-    HeadersOnly -> [qc|
-      WITH {sourceCTEName} AS ({mutateQuery})
-      SELECT {cols}
-      FROM (SELECT 1 FROM {sourceCTEName}) _postgrest_t |]
-    Full -> [qc|
-      WITH {sourceCTEName} AS ({mutateQuery})
-      SELECT {cols}
-      FROM ({selectQuery}) _postgrest_t |]
-
-  cols = intercalate ", " [
-      "'' AS total_result_set", -- when updateing it does not make sense
-      "pg_catalog.count(_postgrest_t) AS page_total",
-      if wantHdrs
-         then locationF pKeys
-         else noLocationF <> " AS header",
-      if rep == Full
-         then bodyF <> " AS body"
-         else "''"
-    ]
-
-  bodyF
-    | asCsv = asCsvF
-    | wantSingle = asJsonSingleF
-    | otherwise = asJsonF
-
-type ProcResults = (Maybe Int64, Int64, ByteString)
-callProc :: QualifiedIdentifier -> JSON.Object -> Bool -> SqlQuery -> SqlQuery -> NonnegRange ->
-  Bool -> Bool -> Bool -> Bool -> Bool -> Maybe FieldName -> H.Query () (Maybe ProcResults)
-callProc qi params returnsScalar selectQuery countQuery _ countTotal isSingle paramsAsJson asCsv asBinary binaryField =
-  unicodeStatement sql HE.unit decodeProc True
-  where
-    sql =
-     if returnsScalar then [qc|
-       WITH {sourceCTEName} AS ({_callSql})
-       SELECT
-         {countResultF} AS total_result_set,
-         1 AS page_total,
-         {scalarBodyF} as body
-       FROM ({selectQuery}) _postgrest_t;|]
-     else [qc|
-       WITH {sourceCTEName} AS ({_callSql})
-       SELECT
-         {countResultF} AS total_result_set,
-         pg_catalog.count(_postgrest_t) AS page_total,
-         {bodyF} as body
-       FROM ({selectQuery}) _postgrest_t;|]
-
-    countResultF = if countTotal then "( "<> countQuery <> ")" else "null::bigint" :: Text
-    _args = if paramsAsJson
-                then insertableValueWithType "json" $ JSON.Object params
-                else intercalate "," $ map _assignment (HM.toList params)
-    _procName = qiName qi
-    _assignment (n,v) = pgFmtIdent n <> ":=" <> insertableValue v
-    _callSql = [qc|select * from {fromQi qi}({_args}) |] :: Text
-    decodeProc = HD.maybeRow procRow
-    procRow = (,,) <$> HD.nullableValue HD.int8 <*> HD.value HD.int8
-                   <*> HD.value HD.bytea
-    scalarBodyF
-     | asBinary = asBinaryF _procName
-     | otherwise = "(row_to_json(_postgrest_t)->" <> pgFmtLit _procName <> ")::character varying"
-
-    bodyF
-     | isSingle = asJsonSingleF
-     | asCsv = asCsvF
-     | isJust binaryField = asBinaryF $ fromJust binaryField
-     | otherwise = asJsonF
-
-pgFmtIdent :: SqlFragment -> SqlFragment
-pgFmtIdent x = "\"" <> replace "\"" "\"\"" (trimNullChars $ toS x) <> "\""
-
-pgFmtLit :: SqlFragment -> SqlFragment
-pgFmtLit x =
- let trimmed = trimNullChars x
-     escaped = "'" <> replace "'" "''" trimmed <> "'"
-     slashed = replace "\\" "\\\\" escaped in
- if "\\" `isInfixOf` escaped
-   then "E" <> slashed
-   else slashed
-
-requestToCountQuery :: Schema -> DbRequest -> SqlQuery
-requestToCountQuery _ (DbMutate _) = undefined
-requestToCountQuery schema (DbRead (Node (Select _ _ logicForest _ _, (mainTbl, _, _, _)) _)) =
- unwords [
-   "SELECT pg_catalog.count(*)",
-   "FROM ", fromQi qi,
-    ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) filteredLogic)) `emptyOnFalse` null filteredLogic
-   ]
- where
-   qi = removeSourceCTESchema schema mainTbl
-   -- all foreing key filters are root nodes(see addFilterToLogicForest), only those are filtered
-   nonFKRoot :: LogicTree -> Bool
-   nonFKRoot (Stmnt (Filter _ Operation{expr=(_, VForeignKey _ _)})) = False
-   nonFKRoot (Stmnt _) = True
-   nonFKRoot Expr{} = True
-   filteredLogic = filter nonFKRoot logicForest
-
-requestToQuery :: Schema -> Bool -> DbRequest -> SqlQuery
-requestToQuery schema isParent (DbRead (Node (Select colSelects tbls logicForest ord range, (nodeName, maybeRelation, _, _)) forest)) =
-  query
-  where
-    mainTbl = fromMaybe nodeName (tableName . relTable <$> maybeRelation)
-    qi = removeSourceCTESchema schema mainTbl
-    toQi = removeSourceCTESchema schema
-    query = unwords [
-      "SELECT ", intercalate ", " (map (pgFmtSelectItem qi) colSelects ++ selects),
-      "FROM ", intercalate ", " (map (fromQi . toQi) tbls),
-      unwords joins,
-      ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest)) `emptyOnFalse` null logicForest,
-      orderF (fromMaybe [] ord),
-      if isParent then "" else limitF range
-      ]
-    orderF ts =
-        if null ts
-            then ""
-            else "ORDER BY " <> clause
-        where
-            clause = intercalate "," (map queryTerm ts)
-            queryTerm :: OrderTerm -> Text
-            queryTerm t = " "
-                <> toS (pgFmtField qi $ otTerm t) <> " "
-                <> maybe "" show (otDirection t) <> " "
-                <> maybe "" show (otNullOrder t) <> " "
-    (joins, selects) = foldr getQueryParts ([],[]) forest
-
-    getQueryParts :: Tree ReadNode -> ([SqlFragment], [SqlFragment]) -> ([SqlFragment], [SqlFragment])
-    getQueryParts (Node n@(_, (name, Just Relation{relType=Child,relTable=Table{tableName=table}}, alias, _)) forst) (j,s) = (j,sel:s)
-      where
-        sel = "COALESCE(("
-           <> "SELECT array_to_json(array_agg(row_to_json("<>pgFmtIdent table<>"))) "
-           <> "FROM (" <> subquery <> ") " <> pgFmtIdent table
-           <> "), '[]') AS " <> pgFmtIdent (fromMaybe name alias)
-           where subquery = requestToQuery schema False (DbRead (Node n forst))
-    getQueryParts (Node n@(_, (name, Just r@Relation{relType=Parent,relTable=Table{tableName=table}}, alias, _)) forst) (j,s) = (joi:j,sel:s)
-      where
-        node_name = fromMaybe name alias
-        local_table_name = table <> "_" <> node_name
-        replaceTableName localTableName (Filter a (Operation b (c, VForeignKey (QualifiedIdentifier "" _) d))) = Filter a (Operation b (c, VForeignKey (QualifiedIdentifier "" localTableName) d))
-        replaceTableName _ x = x
-        sel = "row_to_json(" <> pgFmtIdent local_table_name <> ".*) AS " <> pgFmtIdent node_name
-        joi = " LEFT OUTER JOIN ( " <> subquery <> " ) AS " <> pgFmtIdent local_table_name  <>
-              " ON " <> intercalate " AND " ( map (pgFmtFilter qi . replaceTableName local_table_name) (getJoinFilters r) )
-          where subquery = requestToQuery schema True (DbRead (Node n forst))
-    getQueryParts (Node n@(_, (name, Just Relation{relType=Many,relTable=Table{tableName=table}}, alias, _)) forst) (j,s) = (j,sel:s)
-      where
-        sel = "COALESCE (("
-           <> "SELECT array_to_json(array_agg(row_to_json("<>pgFmtIdent table<>"))) "
-           <> "FROM (" <> subquery <> ") " <> pgFmtIdent table
-           <> "), '[]') AS " <> pgFmtIdent (fromMaybe name alias)
-           where subquery = requestToQuery schema False (DbRead (Node n forst))
-    --the following is just to remove the warning
-    --getQueryParts is not total but requestToQuery is called only after addJoinConditions which ensures the only
-    --posible relations are Child Parent Many
-    getQueryParts _ _ = undefined
-requestToQuery schema _ (DbMutate (Insert mainTbl (PayloadJSON rows) returnings)) =
-  insInto <> vals <> ret
-  where qi = QualifiedIdentifier schema mainTbl
-        cols = map pgFmtIdent $ fromMaybe [] (HM.keys <$> (rows V.!? 0))
-        colsString = intercalate ", " cols
-        insInto = unwords [ "INSERT INTO" , fromQi qi,
-            if T.null colsString then "" else "(" <> colsString <> ")"
-          ]
-        vals = unwords $
-          if T.null colsString
-            then if V.null rows then ["SELECT null WHERE false"] else ["DEFAULT VALUES"]
-            else ["SELECT", colsString, "FROM json_populate_recordset(null::" , fromQi qi, ", $1)"]
-        ret = if null returnings
-                  then ""
-                  else unwords [" RETURNING ", intercalate ", " (map (pgFmtColumn qi) returnings)]
-requestToQuery schema _ (DbMutate (Update mainTbl (PayloadJSON rows) logicForest returnings)) =
-  case rows V.!? 0 of
-    Just obj ->
-      let assignments = map
-            (\(k,v) -> pgFmtIdent k <> "=" <> insertableValue v) $ HM.toList obj in
-      unwords [
-        "UPDATE ", fromQi qi,
-        " SET " <> intercalate "," assignments <> " ",
-        ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest)) `emptyOnFalse` null logicForest,
-        ("RETURNING " <> intercalate ", " (map (pgFmtColumn qi) returnings)) `emptyOnFalse` null returnings
-        ]
-    Nothing -> undefined
-  where
-    qi = QualifiedIdentifier schema mainTbl
-requestToQuery schema _ (DbMutate (Delete mainTbl logicForest returnings)) =
-  query
-  where
-    qi = QualifiedIdentifier schema mainTbl
-    query = unwords [
-      "DELETE FROM ", fromQi qi,
-      ("WHERE " <> intercalate " AND " (map (pgFmtLogicTree qi) logicForest)) `emptyOnFalse` null logicForest,
-      ("RETURNING " <> intercalate ", " (map (pgFmtColumn qi) returnings)) `emptyOnFalse` null returnings
-      ]
-
-sourceCTEName :: SqlFragment
-sourceCTEName = "pg_source"
-
-removeSourceCTESchema :: Schema -> TableName -> QualifiedIdentifier
-removeSourceCTESchema schema tbl = QualifiedIdentifier (if tbl == sourceCTEName then "" else schema) tbl
-
-unquoted :: JSON.Value -> Text
-unquoted (JSON.String t) = t
-unquoted (JSON.Number n) =
-  toS $ formatScientific Fixed (if isInteger n then Just 0 else Nothing) n
-unquoted (JSON.Bool b) = show b
-unquoted v = toS $ JSON.encode v
-
--- private functions
-asCsvF :: SqlFragment
-asCsvF = asCsvHeaderF <> " || '\n' || " <> asCsvBodyF
-  where
-    asCsvHeaderF =
-      "(SELECT coalesce(string_agg(a.k, ','), '')" <>
-      "  FROM (" <>
-      "    SELECT json_object_keys(r)::TEXT as k" <>
-      "    FROM ( " <>
-      "      SELECT row_to_json(hh) as r from " <> sourceCTEName <> " as hh limit 1" <>
-      "    ) s" <>
-      "  ) a" <>
-      ")"
-    asCsvBodyF = "coalesce(string_agg(substring(_postgrest_t::text, 2, length(_postgrest_t::text) - 2), '\n'), '')"
-
-asJsonF :: SqlFragment
-asJsonF = "coalesce(array_to_json(array_agg(row_to_json(_postgrest_t))), '[]')::character varying"
-
-asJsonSingleF :: SqlFragment --TODO! unsafe when the query actually returns multiple rows, used only on inserting and returning single element
-asJsonSingleF = "coalesce(string_agg(row_to_json(_postgrest_t)::text, ','), '')::character varying "
-
-asBinaryF :: FieldName -> SqlFragment
-asBinaryF fieldName = "coalesce(string_agg(_postgrest_t." <> pgFmtIdent fieldName <> ", ''), '')"
-
-locationF :: [Text] -> SqlFragment
-locationF pKeys =
-    "(" <>
-    " WITH s AS (SELECT row_to_json(ss) as r from " <> sourceCTEName <> " as ss  limit 1)" <>
-    " SELECT array_agg(json_data.key || '=' || coalesce('eq.' || json_data.value, 'is.null'))" <>
-    " FROM s, json_each_text(s.r) AS json_data" <>
-    (
-      if null pKeys
-      then ""
-      else " WHERE json_data.key IN ('" <> intercalate "','" pKeys <> "')"
-    ) <> ")"
-
-limitF :: NonnegRange -> SqlFragment
-limitF r  = if r == allRange
-  then ""
-  else "LIMIT " <> limit <> " OFFSET " <> offset
-  where
-    limit  = maybe "ALL" show $ rangeLimit r
-    offset = show $ rangeOffset r
-
-fromQi :: QualifiedIdentifier -> SqlFragment
-fromQi t = (if s == "" then "" else pgFmtIdent s <> ".") <> pgFmtIdent n
-  where
-    n = qiName t
-    s = qiSchema t
-
-getJoinFilters :: Relation -> [Filter]
-getJoinFilters (Relation t cols ft fcs typ lt lc1 lc2) =
-  case typ of
-    Child  -> zipWith (toFilter tN ftN) cols fcs
-    Parent -> zipWith (toFilter tN ftN) cols fcs
-    Many   -> zipWith (toFilter tN ltN) cols (fromMaybe [] lc1) ++ zipWith (toFilter ftN ltN) fcs (fromMaybe [] lc2)
-    Root   -> undefined --error "undefined getJoinFilters"
-  where
-    s = if typ == Parent then "" else tableSchema t
-    tN = tableName t
-    ftN = tableName ft
-    ltN = fromMaybe "" (tableName <$> lt)
-    toFilter :: Text -> Text -> Column -> Column -> Filter
-    toFilter tb ftb c fc = Filter (colName c, Nothing) (Operation False ("=", VForeignKey (QualifiedIdentifier s tb) (ForeignKey fc{colTable=(colTable fc){tableName=ftb}})))
-
-unicodeStatement :: Text -> HE.Params a -> HD.Result b -> Bool -> H.Query a b
-unicodeStatement = H.statement . T.encodeUtf8
-
-emptyOnFalse :: Text -> Bool -> Text
-emptyOnFalse val cond = if cond then "" else val
-
-insertableValue :: JSON.Value -> SqlFragment
-insertableValue JSON.Null = "null"
-insertableValue v = (<> "::unknown") . pgFmtLit $ unquoted v
-
-insertableValueWithType :: Text -> JSON.Value -> SqlFragment
-insertableValueWithType t v =
-  pgFmtLit (unquoted v) <> "::" <> t
-
-pgFmtColumn :: QualifiedIdentifier -> Text -> SqlFragment
-pgFmtColumn table "*" = fromQi table <> ".*"
-pgFmtColumn table c = fromQi table <> "." <> pgFmtIdent c
-
-pgFmtField :: QualifiedIdentifier -> Field -> SqlFragment
-pgFmtField table (c, jp) = pgFmtColumn table c <> pgFmtJsonPath jp
-
-pgFmtSelectItem :: QualifiedIdentifier -> SelectItem -> SqlFragment
-pgFmtSelectItem table (f@(_, jp), Nothing, alias, _) = pgFmtField table f <> pgFmtAs jp alias
-pgFmtSelectItem table (f@(_, jp), Just cast, alias, _) = "CAST (" <> pgFmtField table f <> " AS " <> cast <> " )" <> pgFmtAs jp alias
-
-pgFmtFilter :: QualifiedIdentifier -> Filter -> SqlFragment
-pgFmtFilter table (Filter fld (Operation hasNot_ ex)) = notOp <> " " <> case ex of
-   (op, VText val) -> pgFmtFieldOp op <> " " <> case op of
-     "like"  -> unknownLiteral (T.map star val)
-     "ilike" -> unknownLiteral (T.map star val)
-     -- TODO: The '@@' was deprecated, remove in v0.5.0.0
-     "@@"    -> "to_tsquery(" <> unknownLiteral val <> ") "
-     "fts"   -> "to_tsquery(" <> unknownLiteral val <> ") "
-     "is"    -> whiteList val
-     "isnot" -> whiteList val
-     _       -> unknownLiteral val
-   (op, VTextL vals) -> pgFmtIn op vals -- in and notin
-   (op, VForeignKey fQi (ForeignKey Column{colTable=Table{tableName=fTableName}, colName=fColName})) ->
-     pgFmtField fQi fld <> " " <> sqlOperator op <> " " <> pgFmtColumn (removeSourceCTESchema (qiSchema fQi) fTableName) fColName
- where
-   pgFmtFieldOp op = pgFmtField table fld <> " " <> sqlOperator op
-   sqlOperator o = HM.lookupDefault "=" o operators
-   notOp = if hasNot_ then "NOT" else ""
-   star c = if c == '*' then '%' else c
-   unknownLiteral = (<> "::unknown ") . pgFmtLit
-   whiteList :: Text -> SqlFragment
-   whiteList v = fromMaybe
-     (toS (pgFmtLit v) <> "::unknown ")
-     (find ((==) . toLower $ v) ["null","true","false"])
-   pgFmtIn :: Operator -> [Text] -> SqlFragment
-   pgFmtIn op vals =
-    -- Workaround because for postgresql "col IN ()" is invalid syntax, we instead do "col = any('{}')"
-    let emptyValForIn o = (if "not" `isInfixOf` o then "NOT " else "") -- handle case of "notin" operator
-                          <> pgFmtField table fld <> " = any('{}') " in
-    case T.null <$> headMay vals of
-      Just isNull -> if isNull && length vals == 1
-                        then emptyValForIn op
-                        else pgFmtFieldOp op <> "(" <> intercalate ", " (map unknownLiteral vals) <> ") "
-      Nothing -> emptyValForIn op
-
-pgFmtLogicTree :: QualifiedIdentifier -> LogicTree -> SqlFragment
-pgFmtLogicTree qi (Expr hasNot_ op forest) = notOp <> " (" <> intercalate (" " <> show op <> " ") (pgFmtLogicTree qi <$> forest) <> ")"
-  where notOp =  if hasNot_ then "NOT" else ""
-pgFmtLogicTree qi (Stmnt flt) = pgFmtFilter qi flt
-
-pgFmtJsonPath :: Maybe JsonPath -> SqlFragment
-pgFmtJsonPath (Just [x]) = "->>" <> pgFmtLit x
-pgFmtJsonPath (Just (x:xs)) = "->" <> pgFmtLit x <> pgFmtJsonPath ( Just xs )
-pgFmtJsonPath _ = ""
-
-pgFmtAs :: Maybe JsonPath -> Maybe Alias -> SqlFragment
-pgFmtAs Nothing Nothing = ""
-pgFmtAs (Just xx) Nothing = case lastMay xx of
-  Just alias -> " AS " <> pgFmtIdent alias
-  Nothing -> ""
-pgFmtAs _ (Just alias) = " AS " <> pgFmtIdent alias
-
-pgFmtEnvVar :: Text -> (Text, Text) -> SqlFragment
-pgFmtEnvVar prefix (k, v) =
-  "set local " <> pgFmtIdent (prefix <> k) <> " = " <> pgFmtLit v <> ";"
-
-trimNullChars :: Text -> Text
-trimNullChars = T.takeWhile (/= '\x0')

src/PostgREST/RangeQuery.hs

@@ -1,3 +1,7 @@
+{-|
+Module      : PostgREST.RangeQuery
+Description : Logic regarding the `Range`/`Content-Range` headers and `limit`/`offset` querystring arguments.
+-}
 module PostgREST.RangeQuery (
   rangeParse
 , rangeRequested
@@ -7,21 +11,23 @@ module PostgREST.RangeQuery (
 , rangeGeq
 , allRange
 , NonnegRange
+, rangeStatusHeader
+, contentRangeH
 ) where
 
+import qualified Data.ByteString.Char8 as BS
 
-import           Control.Applicative
-import           Network.HTTP.Types.Header
+import Data.List       (lookup)
+import Text.Regex.TDFA ((=~))
 
-import qualified Data.ByteString.Char8     as BS
-import           Data.Ranged.Boundaries
-import           Data.Ranged.Ranges
+import Control.Applicative
+import Data.Ranged.Boundaries
+import Data.Ranged.Ranges
+import Network.HTTP.Types.Header
+import Network.HTTP.Types.Status
 
-import           Text.Regex.TDFA           ((=~))
-
-import Data.List (lookup)
-
-import           Protolude
+import Protolude      hiding (toS)
+import Protolude.Conv (toS)
 
 type NonnegRange = Range Integer
 
@@ -32,14 +38,13 @@ rangeParse range = do
   case listToMaybe (range =~ rangeRegex :: [[BS.ByteString]]) of
     Just parsedRange ->
       let [_, mLower, mUpper] = readMaybe . toS <$> parsedRange
-          lower         = fromMaybe emptyRange   (rangeGeq <$> mLower)
-          upper         = fromMaybe allRange (rangeLeq <$> mUpper) in
+          lower         = maybe emptyRange rangeGeq mLower
+          upper         = maybe allRange rangeLeq mUpper in
       rangeIntersection lower upper
     Nothing -> allRange
 
 rangeRequested :: RequestHeaders -> NonnegRange
-rangeRequested headers = fromMaybe allRange $
-  rangeParse <$> lookup hRange headers
+rangeRequested headers = maybe allRange rangeParse $ lookup hRange headers
 
 restrictRange :: Maybe Integer -> NonnegRange -> NonnegRange
 restrictRange Nothing r = r
@@ -57,7 +62,7 @@ rangeOffset :: NonnegRange -> Integer
 rangeOffset range =
   case rangeLower range of
     BoundaryBelow lower -> lower
-    _ -> panic "range without lower bound" -- should never happen
+    _                   -> panic "range without lower bound" -- should never happen
 
 rangeGeq :: Integer -> NonnegRange
 rangeGeq n =
@@ -69,3 +74,30 @@ allRange = rangeGeq 0
 rangeLeq :: Integer -> NonnegRange
 rangeLeq n =
   Range BoundaryBelowAll (BoundaryAbove n)
+
+rangeStatusHeader :: NonnegRange -> Int64 -> Maybe Int64 -> (Status, Header)
+rangeStatusHeader topLevelRange queryTotal tableTotal =
+  let lower = rangeOffset topLevelRange
+      upper = lower + toInteger queryTotal - 1
+      contentRange = contentRangeH lower upper (toInteger <$> tableTotal)
+      status = rangeStatus lower upper (toInteger <$> tableTotal)
+  in (status, contentRange)
+  where
+    rangeStatus :: Integer -> Integer -> Maybe Integer -> Status
+    rangeStatus _ _ Nothing = status200
+    rangeStatus lower upper (Just total)
+      | lower > total               = status416 -- 416 Range Not Satisfiable
+      | (1 + upper - lower) < total = status206 -- 206 Partial Content
+      | otherwise                   = status200 -- 200 OK
+
+contentRangeH :: (Integral a, Show a) => a -> a -> Maybe a -> Header
+contentRangeH lower upper total =
+    ("Content-Range", toUtf8 headerValue)
+    where
+      headerValue   = rangeString <> "/" <> totalString :: Text
+      rangeString
+        | totalNotZero && fromInRange = show lower <> "-" <> show upper
+        | otherwise = "*"
+      totalString   = maybe "*" show total
+      totalNotZero  = Just 0 /= total
+      fromInRange   = lower <= upper

src/PostgREST/Request/ApiRequest.hs

@@ -0,0 +1,516 @@
+{-|
+Module      : PostgREST.Request.ApiRequest
+Description : PostgREST functions to translate HTTP request to a domain type called ApiRequest.
+-}
+{-# LANGUAGE LambdaCase      #-}
+{-# LANGUAGE MultiWayIf      #-}
+{-# LANGUAGE NamedFieldPuns  #-}
+{-# LANGUAGE RecordWildCards #-}
+
+module PostgREST.Request.ApiRequest
+  ( ApiRequest(..)
+  , InvokeMethod(..)
+  , ContentType(..)
+  , Action(..)
+  , Target(..)
+  , PayloadJSON(..)
+  , userApiRequest
+  ) where
+
+import qualified Data.Aeson           as JSON
+import qualified Data.ByteString      as BS
+import qualified Data.ByteString.Lazy as BL
+import qualified Data.CaseInsensitive as CI
+import qualified Data.Csv             as CSV
+import qualified Data.HashMap.Strict  as M
+import qualified Data.List            as L
+import qualified Data.Set             as S
+import qualified Data.Text            as T
+import qualified Data.Vector          as V
+
+import Control.Arrow             ((***))
+import Data.Aeson.Types          (emptyArray, emptyObject)
+import Data.List                 (last, lookup, partition, union)
+import Data.List.NonEmpty        (head)
+import Data.Maybe                (fromJust)
+import Data.Ranged.Boundaries    (Boundary (..))
+import Data.Ranged.Ranges        (Range (..), emptyRange,
+                                  rangeIntersection)
+import Network.HTTP.Base         (urlEncodeVars)
+import Network.HTTP.Types.Header (hAuthorization, hCookie)
+import Network.HTTP.Types.URI    (parseQueryReplacePlus,
+                                  parseSimpleQuery)
+import Network.Wai               (Request (..))
+import Network.Wai.Parse         (parseHttpAccept)
+import Web.Cookie                (parseCookies)
+
+import PostgREST.Config                  (AppConfig (..),
+                                          OpenAPIMode (..))
+import PostgREST.ContentType             (ContentType (..))
+import PostgREST.DbStructure             (DbStructure (..))
+import PostgREST.DbStructure.Identifiers (FieldName,
+                                          QualifiedIdentifier (..),
+                                          Schema)
+import PostgREST.DbStructure.Proc        (PgArg (..),
+                                          ProcDescription (..),
+                                          ProcsMap)
+import PostgREST.Error                   (ApiRequestError (..))
+import PostgREST.Query.SqlFragment       (ftsOperators, operators)
+import PostgREST.RangeQuery              (NonnegRange, allRange,
+                                          rangeGeq, rangeLimit,
+                                          rangeOffset, rangeRequested,
+                                          restrictRange)
+import PostgREST.Request.Parsers         (pRequestColumns)
+import PostgREST.Request.Preferences     (PreferCount (..),
+                                          PreferParameters (..),
+                                          PreferRepresentation (..),
+                                          PreferResolution (..),
+                                          PreferTransaction (..))
+
+import qualified PostgREST.ContentType as ContentType
+
+import Protolude      hiding (head, toS)
+import Protolude.Conv (toS)
+
+
+type RequestBody = BL.ByteString
+
+data PayloadJSON
+  = ProcessedJSON -- ^ Cached attributes of a JSON payload
+      { pjRaw  :: BL.ByteString
+      -- ^ This is the raw ByteString that comes from the request body.  We
+      -- cache this instead of an Aeson Value because it was detected that for
+      -- large payloads the encoding had high memory usage, see
+      -- https://github.com/PostgREST/postgrest/pull/1005 for more details
+      , pjKeys :: S.Set Text
+      -- ^ Keys of the object or if it's an array these keys are guaranteed to
+      -- be the same across all its objects
+      }
+  | RawJSON { pjRaw  :: BL.ByteString }
+
+data InvokeMethod = InvHead | InvGet | InvPost deriving Eq
+-- | Types of things a user wants to do to tables/views/procs
+data Action = ActionCreate       | ActionRead{isHead :: Bool}
+            | ActionUpdate       | ActionDelete
+            | ActionSingleUpsert | ActionInvoke InvokeMethod
+            | ActionInfo         | ActionInspect{isHead :: Bool}
+            deriving Eq
+-- | The path info that will be mapped to a target (used to handle validations and errors before defining the Target)
+data Path
+  = PathInfo
+      { pSchema        :: Schema,
+        pName          :: Text,
+        pHasRpc        :: Bool,
+        pIsDefaultSpec :: Bool,
+        pIsRootSpec    :: Bool
+      }
+  | PathUnknown
+-- | The target db object of a user action
+data Target = TargetIdent QualifiedIdentifier
+            | TargetProc{tProc :: ProcDescription, tpIsRootSpec :: Bool}
+            | TargetDefaultSpec{tdsSchema :: Schema} -- The default spec offered at root "/"
+            | TargetUnknown
+
+-- | RPC query param value `/rpc/func?v=<value>`, used for VARIADIC functions on form-urlencoded POST and GETs
+-- | It can be fixed `?v=1` or repeated `?v=1&v=2&v=3.
+data RpcParamValue = Fixed Text | Variadic [Text]
+instance JSON.ToJSON RpcParamValue where
+  toJSON (Fixed    v) = JSON.toJSON v
+  toJSON (Variadic v) = JSON.toJSON v
+
+toRpcParamValue :: ProcDescription -> (Text, Text) -> (Text, RpcParamValue)
+toRpcParamValue proc (k, v) | argIsVariadic k = (k, Variadic [v])
+                            | otherwise       = (k, Fixed v)
+  where
+    argIsVariadic arg = isJust $ find (\PgArg{pgaName, pgaVar} -> pgaName == arg && pgaVar) $ pdArgs proc
+
+-- | Convert rpc params `/rpc/func?a=val1&b=val2` to json `{"a": "val1", "b": "val2"}
+jsonRpcParams :: ProcDescription -> [(Text, Text)] -> PayloadJSON
+jsonRpcParams proc prms =
+  if not $ pdHasVariadic proc then -- if proc has no variadic arg, save steps and directly convert to json
+    ProcessedJSON (JSON.encode $ M.fromList $ second JSON.toJSON <$> prms) (S.fromList $ fst <$> prms)
+  else
+    let paramsMap = M.fromListWith mergeParams $ toRpcParamValue proc <$> prms in
+    ProcessedJSON (JSON.encode paramsMap) (S.fromList $ M.keys paramsMap)
+  where
+    mergeParams :: RpcParamValue -> RpcParamValue -> RpcParamValue
+    mergeParams (Variadic a) (Variadic b) = Variadic $ b ++ a
+    mergeParams v _                       = v -- repeated params for non-variadic arguments are not merged
+
+targetToJsonRpcParams :: Maybe Target -> [(Text, Text)] -> Maybe PayloadJSON
+targetToJsonRpcParams target params =
+  case target of
+    Just TargetProc{tProc} -> Just $ jsonRpcParams tProc params
+    _                      -> Nothing
+
+{-|
+  Describes what the user wants to do. This data type is a
+  translation of the raw elements of an HTTP request into domain
+  specific language.  There is no guarantee that the intent is
+  sensible, it is up to a later stage of processing to determine
+  if it is an action we are able to perform.
+-}
+data ApiRequest = ApiRequest {
+    iAction               :: Action                           -- ^ Similar but not identical to HTTP verb, e.g. Create/Invoke both POST
+  , iRange                :: M.HashMap ByteString NonnegRange -- ^ Requested range of rows within response
+  , iTopLevelRange        :: NonnegRange                      -- ^ Requested range of rows from the top level
+  , iTarget               :: Target                           -- ^ The target, be it calling a proc or accessing a table
+  , iPayload              :: Maybe PayloadJSON                -- ^ Data sent by client and used for mutation actions
+  , iPreferRepresentation :: PreferRepresentation             -- ^ If client wants created items echoed back
+  , iPreferParameters     :: Maybe PreferParameters           -- ^ How to pass parameters to a stored procedure
+  , iPreferCount          :: Maybe PreferCount                -- ^ Whether the client wants a result count
+  , iPreferResolution     :: Maybe PreferResolution           -- ^ Whether the client wants to UPSERT or ignore records on PK conflict
+  , iPreferTransaction    :: Maybe PreferTransaction          -- ^ Whether the clients wants to commit or rollback the transaction
+  , iFilters              :: [(Text, Text)]                   -- ^ Filters on the result ("id", "eq.10")
+  , iLogic                :: [(Text, Text)]                   -- ^ &and and &or parameters used for complex boolean logic
+  , iSelect               :: Maybe Text                       -- ^ &select parameter used to shape the response
+  , iOnConflict           :: Maybe Text                       -- ^ &on_conflict parameter used to upsert on specific unique keys
+  , iColumns              :: S.Set FieldName                  -- ^ parsed colums from &columns parameter and payload
+  , iOrder                :: [(Text, Text)]                   -- ^ &order parameters for each level
+  , iCanonicalQS          :: ByteString                       -- ^ Alphabetized (canonical) request query string for response URLs
+  , iJWT                  :: Text                             -- ^ JSON Web Token
+  , iHeaders              :: [(ByteString, ByteString)]       -- ^ HTTP request headers
+  , iCookies              :: [(ByteString, ByteString)]       -- ^ Request Cookies
+  , iPath                 :: ByteString                       -- ^ Raw request path
+  , iMethod               :: ByteString                       -- ^ Raw request method
+  , iProfile              :: Maybe Schema                     -- ^ The request profile for enabling use of multiple schemas. Follows the spec in hhttps://www.w3.org/TR/dx-prof-conneg/ttps://www.w3.org/TR/dx-prof-conneg/.
+  , iSchema               :: Schema                           -- ^ The request schema. Can vary depending on iProfile.
+  , iAcceptContentType    :: ContentType
+  }
+
+-- | Examines HTTP request and translates it into user intent.
+userApiRequest :: AppConfig -> DbStructure -> Request -> RequestBody -> Either ApiRequestError ApiRequest
+userApiRequest conf@AppConfig{..} dbStructure req reqBody
+  | isJust profile && fromJust profile `notElem` configDbSchemas = Left $ UnacceptableSchema $ toList configDbSchemas
+  | isTargetingProc && method `notElem` ["HEAD", "GET", "POST"] = Left ActionInappropriate
+  | topLevelRange == emptyRange = Left InvalidRange
+  | shouldParsePayload && isLeft payload = either (Left . InvalidBody . toS) witness payload
+  | isLeft parsedColumns = either Left witness parsedColumns
+  | otherwise = do
+     acceptContentType <- findAcceptContentType conf action path accepts
+     checkedTarget <- target
+     return ApiRequest {
+      iAction = action
+      , iTarget = checkedTarget
+      , iRange = ranges
+      , iTopLevelRange = topLevelRange
+      , iPayload = relevantPayload
+      , iPreferRepresentation = representation
+      , iPreferParameters  = if | hasPrefer (show SingleObject)     -> Just SingleObject
+                                | hasPrefer (show MultipleObjects)  -> Just MultipleObjects
+                                | otherwise                         -> Nothing
+      , iPreferCount       = if | hasPrefer (show ExactCount)       -> Just ExactCount
+                                | hasPrefer (show PlannedCount)     -> Just PlannedCount
+                                | hasPrefer (show EstimatedCount)   -> Just EstimatedCount
+                                | otherwise                         -> Nothing
+      , iPreferResolution  = if | hasPrefer (show MergeDuplicates)  -> Just MergeDuplicates
+                                | hasPrefer (show IgnoreDuplicates) -> Just IgnoreDuplicates
+                                | otherwise                         -> Nothing
+      , iPreferTransaction = if | hasPrefer (show Commit)           -> Just Commit
+                                | hasPrefer (show Rollback)         -> Just Rollback
+                                | otherwise                         -> Nothing
+      , iFilters = filters
+      , iLogic = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["and", "or"] k ]
+      , iSelect = toS <$> join (lookup "select" qParams)
+      , iOnConflict = toS <$> join (lookup "on_conflict" qParams)
+      , iColumns = payloadColumns
+      , iOrder = [(toS k, toS $ fromJust v) | (k,v) <- qParams, isJust v, endingIn ["order"] k ]
+      , iCanonicalQS = toS $ urlEncodeVars
+        . L.sortOn fst
+        . map (join (***) toS . second (fromMaybe BS.empty))
+        $ qString
+      , iJWT = tokenStr
+      , iHeaders = [ (CI.foldedCase k, v) | (k,v) <- hdrs, k /= hCookie]
+      , iCookies = maybe [] parseCookies $ lookupHeader "Cookie"
+      , iPath = rawPathInfo req
+      , iMethod = method
+      , iProfile = profile
+      , iSchema = schema
+      , iAcceptContentType = acceptContentType
+      }
+ where
+  accepts = maybe [CTAny] (map ContentType.decodeContentType . parseHttpAccept) $ lookupHeader "accept"
+  -- queryString with '+' converted to ' '(space)
+  qString = parseQueryReplacePlus True $ rawQueryString req
+  -- rpcQParams = Rpc query params e.g. /rpc/name?param1=val1, similar to filter but with no operator(eq, lt..)
+  (filters, rpcQParams) =
+    case action of
+      ActionInvoke InvGet  -> partitionFlts
+      ActionInvoke InvHead -> partitionFlts
+      _                    -> (flts, [])
+  partitionFlts = partition (liftM2 (||) (isEmbedPath . fst) (hasOperator . snd)) flts
+  flts =
+    [ (toS k, toS $ fromJust v) |
+      (k,v) <- qParams, isJust v,
+      k `notElem` ["select", "columns"],
+      not (endingIn ["order", "limit", "offset", "and", "or"] k) ]
+  hasOperator val = any (`T.isPrefixOf` val) $
+                      ((<> ".") <$> "not":M.keys operators) ++
+                      ((<> "(") <$> M.keys ftsOperators)
+  isEmbedPath = T.isInfixOf "."
+  isTargetingProc = case path of
+    PathInfo{pHasRpc, pIsRootSpec} -> pHasRpc || pIsRootSpec
+    _                              -> False
+  isTargetingDefaultSpec = case path of
+    PathInfo{pIsDefaultSpec=True} -> True
+    _                             -> False
+  contentType = ContentType.decodeContentType . fromMaybe "application/json" $ lookupHeader "content-type"
+  columns
+    | action `elem` [ActionCreate, ActionUpdate, ActionInvoke InvPost] = toS <$> join (lookup "columns" qParams)
+    | otherwise = Nothing
+  parsedColumns = pRequestColumns columns
+  payloadColumns =
+    case (contentType, action) of
+      (_, ActionInvoke InvGet)  -> S.fromList $ fst <$> rpcQParams
+      (_, ActionInvoke InvHead) -> S.fromList $ fst <$> rpcQParams
+      (CTUrlEncoded, _)         -> S.fromList $ map (toS . fst) $ parseSimpleQuery $ toS reqBody
+      _ -> case (relevantPayload, fromRight Nothing parsedColumns) of
+        (Just ProcessedJSON{pjKeys}, _) -> pjKeys
+        (Just RawJSON{}, Just cls)      -> cls
+        _                               -> S.empty
+  payload = case contentType of
+    CTApplicationJSON ->
+      if isJust columns
+        then Right $ RawJSON reqBody
+        else note "All object keys must match" . payloadAttributes reqBody
+               =<< if BL.null reqBody && isTargetingProc
+                     then Right emptyObject
+                     else JSON.eitherDecode reqBody
+    CTTextCSV -> do
+      json <- csvToJson <$> CSV.decodeByName reqBody
+      note "All lines must have same number of fields" $ payloadAttributes (JSON.encode json) json
+    CTUrlEncoded ->
+      let paramsMap = M.fromList $ (toS *** JSON.String . toS) <$> parseSimpleQuery (toS reqBody) in
+      Right $ ProcessedJSON (JSON.encode paramsMap) $ S.fromList (M.keys paramsMap)
+    ct ->
+      Left $ toS $ "Content-Type not acceptable: " <> ContentType.toMime ct
+  topLevelRange = fromMaybe allRange $ M.lookup "limit" ranges -- if no limit is specified, get all the request rows
+  action =
+    case method of
+      -- The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response
+      -- From https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.4
+      "HEAD"     | isTargetingDefaultSpec -> ActionInspect{isHead=True}
+                 | isTargetingProc        -> ActionInvoke InvHead
+                 | otherwise              -> ActionRead{isHead=True}
+      "GET"      | isTargetingDefaultSpec -> ActionInspect{isHead=False}
+                 | isTargetingProc        -> ActionInvoke InvGet
+                 | otherwise              -> ActionRead{isHead=False}
+      "POST"    -> if isTargetingProc
+                    then ActionInvoke InvPost
+                    else ActionCreate
+      "PATCH"   -> ActionUpdate
+      "PUT"     -> ActionSingleUpsert
+      "DELETE"  -> ActionDelete
+      "OPTIONS" -> ActionInfo
+      _         -> ActionInspect{isHead=False}
+
+  defaultSchema = head configDbSchemas
+  profile
+    | length configDbSchemas <= 1 -- only enable content negotiation by profile when there are multiple schemas specified in the config
+      = Nothing
+    | otherwise = case action of
+        -- POST/PATCH/PUT/DELETE don't use the same header as per the spec
+        ActionCreate         -> contentProfile
+        ActionUpdate         -> contentProfile
+        ActionSingleUpsert   -> contentProfile
+        ActionDelete         -> contentProfile
+        ActionInvoke InvPost -> contentProfile
+        _                    -> acceptProfile
+    where
+      contentProfile = Just $ maybe defaultSchema toS $ lookupHeader "Content-Profile"
+      acceptProfile = Just $ maybe defaultSchema toS $ lookupHeader "Accept-Profile"
+  schema = fromMaybe defaultSchema profile
+  target =
+    let
+      callFindProc procSch procNam = findProc (QualifiedIdentifier procSch procNam) payloadColumns (hasPrefer (show SingleObject)) $ dbProcs dbStructure
+    in
+    case path of
+      PathInfo{pSchema, pName, pHasRpc, pIsRootSpec, pIsDefaultSpec}
+        | pHasRpc || pIsRootSpec -> (`TargetProc` pIsRootSpec) <$> callFindProc pSchema pName
+        | pIsDefaultSpec         -> Right $ TargetDefaultSpec pSchema
+        | otherwise              -> Right $ TargetIdent $ QualifiedIdentifier pSchema pName
+      PathUnknown -> Right TargetUnknown
+
+  shouldParsePayload = case (contentType, action) of
+    (CTUrlEncoded, ActionInvoke InvPost) -> False
+    (_, act)                             -> act `elem` [ActionCreate, ActionUpdate, ActionSingleUpsert, ActionInvoke InvPost]
+  relevantPayload = case (contentType, action) of
+    -- Though ActionInvoke GET/HEAD doesn't really have a payload, we use the payload variable as a way
+    -- to store the query string arguments to the function.
+    (_, ActionInvoke InvGet)             -> targetToJsonRpcParams (rightToMaybe target) rpcQParams
+    (_, ActionInvoke InvHead)            -> targetToJsonRpcParams (rightToMaybe target) rpcQParams
+    (CTUrlEncoded, ActionInvoke InvPost) -> targetToJsonRpcParams (rightToMaybe target) $ (toS *** toS) <$> parseSimpleQuery (toS reqBody)
+    _ | shouldParsePayload               -> rightToMaybe payload
+      | otherwise                        -> Nothing
+  path =
+    case pathInfo req of
+      []             -> case configDbRootSpec of
+                          Just (QualifiedIdentifier pSch pName)     -> PathInfo (if pSch == mempty then schema else pSch) pName False False True
+                          Nothing | configOpenApiMode == OADisabled -> PathUnknown
+                                  | otherwise                       -> PathInfo schema "" False True False
+      [table]        -> PathInfo schema table False False False
+      ["rpc", pName] -> PathInfo schema pName True False False
+      _              -> PathUnknown
+  method          = requestMethod req
+  hdrs            = requestHeaders req
+  qParams         = [(toS k, v)|(k,v) <- qString]
+  lookupHeader    = flip lookup hdrs
+  hasPrefer :: Text -> Bool
+  hasPrefer val   = any (\(h,v) -> h == "Prefer" && val `elem` split v) hdrs
+    where
+        split :: BS.ByteString -> [Text]
+        split = map T.strip . T.split (==',') . toS
+  representation
+    | hasPrefer (show Full)        = Full
+    | hasPrefer (show None)        = None
+    | hasPrefer (show HeadersOnly) = HeadersOnly
+    | otherwise                    = None
+  auth = fromMaybe "" $ lookupHeader hAuthorization
+  tokenStr = case T.split (== ' ') (toS auth) of
+    ("Bearer" : t : _) -> t
+    ("bearer" : t : _) -> t
+    _                  -> ""
+  endingIn:: [Text] -> Text -> Bool
+  endingIn xx key = lastWord `elem` xx
+    where lastWord = last $ T.split (=='.') key
+
+  headerRange = rangeRequested hdrs
+  replaceLast x s = T.intercalate "." $ L.init (T.split (=='.') s) ++ [x]
+  limitParams :: M.HashMap ByteString NonnegRange
+  limitParams  = M.fromList [(toS (replaceLast "limit" k), restrictRange (readMaybe . toS =<< v) allRange) | (k,v) <- qParams, isJust v, endingIn ["limit"] k]
+  offsetParams :: M.HashMap ByteString NonnegRange
+  offsetParams = M.fromList [(toS (replaceLast "limit" k), maybe allRange rangeGeq (readMaybe . toS =<< v)) | (k,v) <- qParams, isJust v, endingIn ["offset"] k]
+
+  urlRange = M.unionWith f limitParams offsetParams
+    where
+      f rl ro = Range (BoundaryBelow o) (BoundaryAbove $ o + l - 1)
+        where
+          l = fromMaybe 0 $ rangeLimit rl
+          o = rangeOffset ro
+  ranges = M.insert "limit" (rangeIntersection headerRange (fromMaybe allRange (M.lookup "limit" urlRange))) urlRange
+
+{-|
+  Find the best match from a list of content types accepted by the
+  client in order of decreasing preference and a list of types
+  producible by the server.  If there is no match but the client
+  accepts */* then return the top server pick.
+-}
+mutuallyAgreeable :: [ContentType] -> [ContentType] -> Maybe ContentType
+mutuallyAgreeable sProduces cAccepts =
+  let exact = listToMaybe $ L.intersect cAccepts sProduces in
+  if isNothing exact && CTAny `elem` cAccepts
+     then listToMaybe sProduces
+     else exact
+
+type CsvData = V.Vector (M.HashMap Text BL.ByteString)
+
+{-|
+  Converts CSV like
+  a,b
+  1,hi
+  2,bye
+
+  into a JSON array like
+  [ {"a": "1", "b": "hi"}, {"a": 2, "b": "bye"} ]
+
+  The reason for its odd signature is so that it can compose
+  directly with CSV.decodeByName
+-}
+csvToJson :: (CSV.Header, CsvData) -> JSON.Value
+csvToJson (_, vals) =
+  JSON.Array $ V.map rowToJsonObj vals
+ where
+  rowToJsonObj = JSON.Object .
+    M.map (\str ->
+        if str == "NULL"
+          then JSON.Null
+          else JSON.String $ toS str
+      )
+
+payloadAttributes :: RequestBody -> JSON.Value -> Maybe PayloadJSON
+payloadAttributes raw json =
+  -- Test that Array contains only Objects having the same keys
+  case json of
+    JSON.Array arr ->
+      case arr V.!? 0 of
+        Just (JSON.Object o) ->
+          let canonicalKeys = S.fromList $ M.keys o
+              areKeysUniform = all (\case
+                JSON.Object x -> S.fromList (M.keys x) == canonicalKeys
+                _ -> False) arr in
+          if areKeysUniform
+            then Just $ ProcessedJSON raw canonicalKeys
+            else Nothing
+        Just _ -> Nothing
+        Nothing -> Just emptyPJArray
+
+    JSON.Object o -> Just $ ProcessedJSON raw (S.fromList $ M.keys o)
+
+    -- truncate everything else to an empty array.
+    _ -> Just emptyPJArray
+  where
+    emptyPJArray = ProcessedJSON (JSON.encode emptyArray) S.empty
+
+findAcceptContentType :: AppConfig -> Action -> Path -> [ContentType] -> Either ApiRequestError ContentType
+findAcceptContentType conf action path accepts =
+  case mutuallyAgreeable (requestContentTypes conf action path) accepts of
+    Just ct ->
+      Right ct
+    Nothing ->
+      Left . ContentTypeError $ map ContentType.toMime accepts
+
+requestContentTypes :: AppConfig -> Action -> Path -> [ContentType]
+requestContentTypes conf action path =
+  case action of
+    ActionRead _    -> defaultContentTypes ++ rawContentTypes conf
+    ActionInvoke _  -> invokeContentTypes
+    ActionInspect _ -> [CTOpenAPI, CTApplicationJSON]
+    ActionInfo      -> [CTTextCSV]
+    _               -> defaultContentTypes
+  where
+    invokeContentTypes =
+      defaultContentTypes
+        ++ rawContentTypes conf
+        ++ [CTOpenAPI | pIsRootSpec path]
+    defaultContentTypes =
+      [CTApplicationJSON, CTSingularJSON, CTTextCSV]
+
+rawContentTypes :: AppConfig -> [ContentType]
+rawContentTypes AppConfig{..} =
+  (ContentType.decodeContentType <$> configRawMediaTypes) `union` [CTOctetStream, CTTextPlain]
+
+{-|
+  Search a pg procedure by its parameters. Since a function can be overloaded, the name is not enough to find it.
+  An overloaded function can have a different volatility or even a different return type.
+-}
+findProc :: QualifiedIdentifier -> S.Set Text -> Bool -> ProcsMap -> Either ApiRequestError ProcDescription
+findProc qi payloadKeys paramsAsSingleObject allProcs =
+  case bestMatch of
+    []     -> Left $ NoRpc (qiSchema qi) (qiName qi) (S.toList payloadKeys) paramsAsSingleObject
+    [proc] -> Right proc
+    procs  -> Left $ AmbiguousRpc (toList procs)
+  where
+    bestMatch =
+      case M.lookup qi allProcs of
+        Nothing     -> []
+        Just [proc] -> [proc | matches proc]
+        Just procs  -> filter matches procs
+    -- Find the exact arguments match
+    matches proc
+      | paramsAsSingleObject = case pdArgs proc of
+                               [arg] -> pgaType arg `elem` ["json", "jsonb"]
+                               _     -> False
+      | otherwise            = case pdArgs proc of
+                               []   -> null payloadKeys
+                               args -> matchesArg args
+    matchesArg args =
+      -- The function's required arguments are separated from the ones with a default value assigned.
+      -- The set of names of those arguments is compared to the set of keys supplied by the client
+      -- 1. If only required arguments are found, the keys must be exactly the same as those arguments
+      -- 2. If only optional arguments are found, the keys must be a subset of those arguments
+      -- 3. If both required and optional arguments are found, the result of taking away the optional arguments
+      --    from the keys must be exactly the same as the required arguments
+      case L.partition pgaReq args of
+        (reqArgs, [])      -> payloadKeys == S.fromList (pgaName <$> reqArgs)
+        ([], defArgs)      -> payloadKeys `S.isSubsetOf` S.fromList (pgaName <$> defArgs)
+        (reqArgs, defArgs) -> payloadKeys `S.difference` S.fromList (pgaName <$> defArgs) == S.fromList (pgaName <$> reqArgs)

src/PostgREST/Request/DbRequestBuilder.hs

@@ -0,0 +1,376 @@
+{-|
+Module      : PostgREST.Request.DbRequestBuilder
+Description : PostgREST database request builder
+
+This module is in charge of building an intermediate
+representation(ReadRequest, MutateRequest) between the HTTP request and the
+final resulting SQL query.
+
+A query tree is built in case of resource embedding. By inferring the
+relationship between tables, join conditions are added for every embedded
+resource.
+-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE LambdaCase            #-}
+{-# LANGUAGE NamedFieldPuns        #-}
+{-# LANGUAGE RecordWildCards       #-}
+
+module PostgREST.Request.DbRequestBuilder
+  ( readRequest
+  , mutateRequest
+  , returningCols
+  ) where
+
+import qualified Data.HashMap.Strict as M
+import qualified Data.Set            as S
+
+import Control.Arrow           ((***))
+import Data.Either.Combinators (mapLeft)
+import Data.List               (delete)
+import Data.Text               (isInfixOf)
+import Data.Tree               (Tree (..))
+
+import PostgREST.DbStructure.Identifiers  (FieldName,
+                                           QualifiedIdentifier (..),
+                                           Schema, TableName)
+import PostgREST.DbStructure.Relationship (Cardinality (..),
+                                           Junction (..),
+                                           Relationship (..))
+import PostgREST.DbStructure.Table        (Column (..), Table (..),
+                                           tableQi)
+import PostgREST.Error                    (ApiRequestError (..),
+                                           Error (..))
+import PostgREST.Query.SqlFragment        (sourceCTEName)
+import PostgREST.RangeQuery               (NonnegRange, allRange,
+                                           restrictRange)
+import PostgREST.Request.ApiRequest       (Action (..),
+                                           ApiRequest (..),
+                                           PayloadJSON (..))
+
+import PostgREST.Request.Parsers
+import PostgREST.Request.Preferences
+import PostgREST.Request.Types
+
+import qualified PostgREST.DbStructure.Relationship as Relationship
+
+import Protolude hiding (from)
+
+-- | Builds the ReadRequest tree on a number of stages.
+-- | Adds filters, order, limits on its respective nodes.
+-- | Adds joins conditions obtained from resource embedding.
+readRequest :: Schema -> TableName -> Maybe Integer -> [Relationship] -> ApiRequest -> Either Error ReadRequest
+readRequest schema rootTableName maxRows allRels apiRequest  =
+  mapLeft ApiRequestError $
+  treeRestrictRange maxRows =<<
+  augmentRequestWithJoin schema rootRels =<<
+  (addFiltersOrdersRanges apiRequest . initReadRequest rootName =<< pRequestSelect sel)
+  where
+    sel = fromMaybe "*" $ iSelect apiRequest -- default to all columns requested (SELECT *) for a non existent ?select querystring param
+    (rootName, rootRels) = rootWithRels schema rootTableName allRels (iAction apiRequest)
+
+-- Get the root table name with its relationships according to the Action type.
+-- This is done because of the shape of the final SQL Query. The mutation cases
+-- are wrapped in a WITH {sourceCTEName}(see Statements.hs).  So we need a FROM
+-- {sourceCTEName} instead of FROM {tableName}.
+rootWithRels :: Schema -> TableName -> [Relationship] -> Action -> (QualifiedIdentifier, [Relationship])
+rootWithRels schema rootTableName allRels action = case action of
+  ActionRead _ -> (QualifiedIdentifier schema rootTableName, allRels) -- normal read case
+  _            -> (QualifiedIdentifier mempty _sourceCTEName, mapMaybe toSourceRel allRels ++ allRels) -- mutation cases and calling proc
+  where
+    _sourceCTEName = decodeUtf8 sourceCTEName
+    -- To enable embedding in the sourceCTEName cases we need to replace the
+    -- foreign key tableName in the Relationship with {sourceCTEName}. This way
+    -- findRel can find relationships with sourceCTEName.
+    toSourceRel :: Relationship -> Maybe Relationship
+    toSourceRel r@Relationship{relTable=t}
+      | rootTableName == tableName t = Just $ r {relTable=t {tableName=_sourceCTEName}}
+      | otherwise                    = Nothing
+
+-- Build the initial tree with a Depth attribute so when a self join occurs we
+-- can differentiate the parent and child tables by having an alias like
+-- "table_depth", this is related to
+-- http://github.com/PostgREST/postgrest/issues/987.
+initReadRequest :: QualifiedIdentifier -> [Tree SelectItem] -> ReadRequest
+initReadRequest rootQi =
+  foldr (treeEntry rootDepth) initial
+  where
+    rootDepth = 0
+    rootSchema = qiSchema rootQi
+    rootName = qiName rootQi
+    initial = Node (Select [] rootQi Nothing [] [] [] [] allRange, (rootName, Nothing, Nothing, Nothing, rootDepth)) []
+    treeEntry :: Depth -> Tree SelectItem -> ReadRequest -> ReadRequest
+    treeEntry depth (Node fld@((fn, _),_,alias, embedHint) fldForest) (Node (q, i) rForest) =
+      let nxtDepth = succ depth in
+      case fldForest of
+        [] -> Node (q {select=fld:select q}, i) rForest
+        _  -> Node (q, i) $
+              foldr (treeEntry nxtDepth)
+              (Node (Select [] (QualifiedIdentifier rootSchema fn) Nothing [] [] [] [] allRange,
+                (fn, Nothing, alias, embedHint, nxtDepth)) [])
+              fldForest:rForest
+
+-- | Enforces the `max-rows` config on the result
+treeRestrictRange :: Maybe Integer -> ReadRequest -> Either ApiRequestError ReadRequest
+treeRestrictRange maxRows request = pure $ nodeRestrictRange maxRows <$> request
+  where
+    nodeRestrictRange :: Maybe Integer -> ReadNode -> ReadNode
+    nodeRestrictRange m (q@Select {range_=r}, i) = (q{range_=restrictRange m r }, i)
+
+augmentRequestWithJoin :: Schema -> [Relationship] -> ReadRequest -> Either ApiRequestError ReadRequest
+augmentRequestWithJoin schema allRels request =
+  addRels schema allRels Nothing request
+  >>= addJoinConditions Nothing
+
+addRels :: Schema -> [Relationship] -> Maybe ReadRequest -> ReadRequest -> Either ApiRequestError ReadRequest
+addRels schema allRels parentNode (Node (query@Select{from=tbl}, (nodeName, _, alias, hint, depth)) forest) =
+  case parentNode of
+    Just (Node (Select{from=parentNodeQi}, _) _) ->
+      let newFrom r = if qiName tbl == nodeName then tableQi (relForeignTable r) else tbl
+          newReadNode = (\r -> (query{from=newFrom r}, (nodeName, Just r, alias, Nothing, depth))) <$> rel
+          rel = findRel schema allRels (qiName parentNodeQi) nodeName hint
+      in
+      Node <$> newReadNode <*> (updateForest . hush $ Node <$> newReadNode <*> pure forest)
+    _ ->
+      let rn = (query, (nodeName, Nothing, alias, Nothing, depth)) in
+      Node rn <$> updateForest (Just $ Node rn forest)
+  where
+    updateForest :: Maybe ReadRequest -> Either ApiRequestError [ReadRequest]
+    updateForest rq = addRels schema allRels rq `traverse` forest
+
+-- Finds a relationship between an origin and a target in the request:
+-- /origin?select=target(*) If more than one relationship is found then the
+-- request is ambiguous and we return an error.  In that case the request can
+-- be disambiguated by adding precision to the target or by using a hint:
+-- /origin?select=target!hint(*) The elements will be matched according to
+-- these rules:
+-- origin = table / view
+-- target = table / view / constraint / column-from-origin
+-- hint   = table / view / constraint / column-from-origin / column-from-target
+-- (hint can take table / view values to aid in finding the junction in an m2m relationship)
+findRel :: Schema -> [Relationship] -> NodeName -> NodeName -> Maybe EmbedHint -> Either ApiRequestError Relationship
+findRel schema allRels origin target hint =
+  case rel of
+    []  -> Left $ NoRelBetween origin target
+    [r] -> Right r
+    -- Here we handle a self reference relationship to not cause a breaking
+    -- change: In a self reference we get two relationships with the same
+    -- foreign key and relTable/relFtable but with different
+    -- cardinalities(m2o/o2m) We output the O2M rel, the M2O rel can be
+    -- obtained by using the origin column as an embed hint.
+    rs@[rel0, rel1]  -> case (relCardinality rel0, relCardinality rel1, relTable rel0 == relTable rel1 && relForeignTable rel0 == relForeignTable rel1) of
+      (O2M cons1, M2O cons2, True) -> if cons1 == cons2 then Right rel0 else Left $ AmbiguousRelBetween origin target rs
+      (M2O cons1, O2M cons2, True) -> if cons1 == cons2 then Right rel1 else Left $ AmbiguousRelBetween origin target rs
+      _                            -> Left $ AmbiguousRelBetween origin target rs
+    rs -> Left $ AmbiguousRelBetween origin target rs
+  where
+    matchFKSingleCol hint_ cols = length cols == 1 && hint_ == (colName <$> head cols)
+    matchConstraint tar card = case card of
+      O2M cons -> tar == Just cons
+      M2O cons -> tar == Just cons
+      _        -> False
+    matchJunction hint_ card = case card of
+      M2M Junction{junTable} -> hint_ == Just (tableName junTable)
+      _                      -> False
+    rel = filter (
+      \Relationship{..} ->
+        -- Both relationship ends need to be on the exposed schema
+        schema == tableSchema relTable && schema == tableSchema relForeignTable &&
+        (
+          -- /projects?select=clients(*)
+          origin == tableName relTable  &&  -- projects
+          target == tableName relForeignTable ||  -- clients
+
+          -- /projects?select=projects_client_id_fkey(*)
+          (
+            origin == tableName relTable &&              -- projects
+            matchConstraint (Just target) relCardinality -- projects_client_id_fkey
+          ) ||
+          -- /projects?select=client_id(*)
+          (
+            origin == tableName relTable &&           -- projects
+            matchFKSingleCol (Just target) relColumns -- client_id
+          )
+        ) && (
+          isNothing hint || -- hint is optional
+
+          -- /projects?select=clients!projects_client_id_fkey(*)
+          matchConstraint hint relCardinality || -- projects_client_id_fkey
+
+          -- /projects?select=clients!client_id(*) or /projects?select=clients!id(*)
+          matchFKSingleCol hint relColumns  || -- client_id
+          matchFKSingleCol hint relForeignColumns || -- id
+
+          -- /users?select=tasks!users_tasks(*) many-to-many between users and tasks
+          matchJunction hint relCardinality -- users_tasks
+        )
+      ) allRels
+
+-- previousAlias is only used for the case of self joins
+addJoinConditions :: Maybe Alias -> ReadRequest -> Either ApiRequestError ReadRequest
+addJoinConditions previousAlias (Node node@(query@Select{from=tbl}, nodeProps@(_, rel, _, _, depth)) forest) =
+  case rel of
+    Just r@Relationship{relCardinality=M2M Junction{junTable}} ->
+      let rq = augmentQuery r in
+      Node (rq{implicitJoins=tableQi junTable:implicitJoins rq}, nodeProps) <$> updatedForest
+    Just r -> Node (augmentQuery r, nodeProps) <$> updatedForest
+    Nothing -> Node node <$> updatedForest
+  where
+    newAlias = case Relationship.isSelfReference <$> rel of
+      Just True
+        | depth /= 0 -> Just (qiName tbl <> "_" <> show depth) -- root node doesn't get aliased
+        | otherwise  -> Nothing
+      _              -> Nothing
+    augmentQuery r =
+      foldr
+        (\jc rq@Select{joinConditions=jcs} -> rq{joinConditions=jc:jcs})
+        query{fromAlias=newAlias}
+        (getJoinConditions previousAlias newAlias r)
+    updatedForest = addJoinConditions newAlias `traverse` forest
+
+-- previousAlias and newAlias are used in the case of self joins
+getJoinConditions :: Maybe Alias -> Maybe Alias -> Relationship -> [JoinCondition]
+getJoinConditions previousAlias newAlias (Relationship Table{tableSchema=tSchema, tableName=tN} cols Table{tableName=ftN} fCols card) =
+  case card of
+    M2M (Junction Table{tableName=jtn} _ jc1 _ jc2) ->
+      zipWith (toJoinCondition tN jtn) cols jc1 ++ zipWith (toJoinCondition ftN jtn) fCols jc2
+    _ ->
+      zipWith (toJoinCondition tN ftN) cols fCols
+  where
+    toJoinCondition :: Text -> Text -> Column -> Column -> JoinCondition
+    toJoinCondition tb ftb c fc =
+      let qi1 = removeSourceCTESchema tSchema tb
+          qi2 = removeSourceCTESchema tSchema ftb in
+        JoinCondition (maybe qi1 (QualifiedIdentifier mempty) previousAlias, colName c)
+                      (maybe qi2 (QualifiedIdentifier mempty) newAlias, colName fc)
+
+    -- On mutation and calling proc cases we wrap the target table in a WITH
+    -- {sourceCTEName} if this happens remove the schema `FROM
+    -- "schema"."{sourceCTEName}"` and use only the `FROM "{sourceCTEName}"`.
+    -- If the schema remains the FROM would be invalid.
+    removeSourceCTESchema :: Schema -> TableName -> QualifiedIdentifier
+    removeSourceCTESchema schema tbl = QualifiedIdentifier (if tbl == decodeUtf8 sourceCTEName then mempty else schema) tbl
+
+addFiltersOrdersRanges :: ApiRequest -> ReadRequest -> Either ApiRequestError ReadRequest
+addFiltersOrdersRanges apiRequest rReq = do
+  rFlts <- foldr addFilter rReq <$> filters
+  rOrds <- foldr addOrder rFlts <$> orders
+  rRngs <- foldr addRange rOrds <$> ranges
+  foldr addLogicTree rRngs      <$> logicForest
+  where
+    filters :: Either ApiRequestError [(EmbedPath, Filter)]
+    filters = pRequestFilter `traverse` flts
+    orders :: Either ApiRequestError [(EmbedPath, [OrderTerm])]
+    orders = pRequestOrder `traverse` iOrder apiRequest
+    ranges :: Either ApiRequestError [(EmbedPath, NonnegRange)]
+    ranges = pRequestRange `traverse` M.toList (iRange apiRequest)
+    logicForest :: Either ApiRequestError [(EmbedPath, LogicTree)]
+    logicForest = pRequestLogicTree `traverse` logFrst
+    action = iAction apiRequest
+    -- there can be no filters on the root table when we are doing insert/update/delete
+    (flts, logFrst) =
+      case action of
+        ActionInvoke _ -> (iFilters apiRequest, iLogic apiRequest)
+        ActionRead _   -> (iFilters apiRequest, iLogic apiRequest)
+        _              -> join (***) (filter (( "." `isInfixOf` ) . fst)) (iFilters apiRequest, iLogic apiRequest)
+
+addFilterToNode :: Filter -> ReadRequest -> ReadRequest
+addFilterToNode flt (Node (q@Select {where_=lf}, i) f) = Node (q{where_=addFilterToLogicForest flt lf}::ReadQuery, i) f
+
+addFilter :: (EmbedPath, Filter) -> ReadRequest -> ReadRequest
+addFilter = addProperty addFilterToNode
+
+addOrderToNode :: [OrderTerm] -> ReadRequest -> ReadRequest
+addOrderToNode o (Node (q,i) f) = Node (q{order=o}, i) f
+
+addOrder :: (EmbedPath, [OrderTerm]) -> ReadRequest -> ReadRequest
+addOrder = addProperty addOrderToNode
+
+addRangeToNode :: NonnegRange -> ReadRequest -> ReadRequest
+addRangeToNode r (Node (q,i) f) = Node (q{range_=r}, i) f
+
+addRange :: (EmbedPath, NonnegRange) -> ReadRequest -> ReadRequest
+addRange = addProperty addRangeToNode
+
+addLogicTreeToNode :: LogicTree -> ReadRequest -> ReadRequest
+addLogicTreeToNode t (Node (q@Select{where_=lf},i) f) = Node (q{where_=t:lf}::ReadQuery, i) f
+
+addLogicTree :: (EmbedPath, LogicTree) -> ReadRequest -> ReadRequest
+addLogicTree = addProperty addLogicTreeToNode
+
+addProperty :: (a -> ReadRequest -> ReadRequest) -> (EmbedPath, a) -> ReadRequest -> ReadRequest
+addProperty f ([], a) rr = f a rr
+addProperty f (targetNodeName:remainingPath, a) (Node rn forest) =
+  case pathNode of
+    Nothing -> Node rn forest -- the property is silenty dropped in the Request does not contain the required path
+    Just tn -> Node rn (addProperty f (remainingPath, a) tn:delete tn forest)
+  where
+    pathNode = find (\(Node (_,(nodeName,_,alias,_,_)) _) -> nodeName == targetNodeName || alias == Just targetNodeName) forest
+
+mutateRequest :: Schema -> TableName -> ApiRequest -> [FieldName] -> ReadRequest -> Either Error MutateRequest
+mutateRequest schema tName apiRequest pkCols readReq = mapLeft ApiRequestError $
+  case action of
+    ActionCreate -> do
+        confCols <- case iOnConflict apiRequest of
+            Nothing    -> pure pkCols
+            Just param -> pRequestOnConflict param
+        pure $ Insert qi (iColumns apiRequest) body ((,) <$> iPreferResolution apiRequest <*> Just confCols) [] returnings
+    ActionUpdate -> Update qi (iColumns apiRequest) body  <$> combinedLogic <*> pure returnings
+    ActionSingleUpsert ->
+      (\flts ->
+        if null (iLogic apiRequest) &&
+           S.fromList (fst <$> iFilters apiRequest) == S.fromList pkCols &&
+           not (null (S.fromList pkCols)) &&
+           all (\case
+              Filter _ (OpExpr False (Op "eq" _)) -> True
+              _                                   -> False) flts
+          then Insert qi (iColumns apiRequest) body (Just (MergeDuplicates, pkCols)) <$> combinedLogic <*> pure returnings
+        else
+          Left InvalidFilters) =<< filters
+    ActionDelete -> Delete qi <$> combinedLogic <*> pure returnings
+    _            -> Left UnsupportedVerb
+  where
+    qi = QualifiedIdentifier schema tName
+    action = iAction apiRequest
+    returnings =
+      if iPreferRepresentation apiRequest == None
+        then []
+        else returningCols readReq pkCols
+    filters = map snd <$> pRequestFilter `traverse` mutateFilters
+    logic = map snd <$> pRequestLogicTree `traverse` logicFilters
+    combinedLogic = foldr addFilterToLogicForest <$> logic <*> filters
+    -- update/delete filters can be only on the root table
+    (mutateFilters, logicFilters) = join (***) onlyRoot (iFilters apiRequest, iLogic apiRequest)
+    onlyRoot = filter (not . ( "." `isInfixOf` ) . fst)
+    body = pjRaw <$> iPayload apiRequest
+
+returningCols :: ReadRequest -> [FieldName] -> [FieldName]
+returningCols rr@(Node _ forest) pkCols
+  -- if * is part of the select, we must not add pk or fk columns manually -
+  -- otherwise those would be selected and output twice
+  | "*" `elem` fldNames = ["*"]
+  | otherwise           = returnings
+  where
+    fldNames = fstFieldNames rr
+    -- Without fkCols, when a mutateRequest to
+    -- /projects?select=name,clients(name) occurs, the RETURNING SQL part would
+    -- be `RETURNING name`(see QueryBuilder).  This would make the embedding
+    -- fail because the following JOIN would need the "client_id" column from
+    -- projects.  So this adds the foreign key columns to ensure the embedding
+    -- succeeds, result would be `RETURNING name, client_id`.
+    fkCols = concat $ mapMaybe (\case
+        Node (_, (_, Just Relationship{relColumns=cols}, _, _, _)) _ -> Just cols
+        _                                                        -> Nothing
+      ) forest
+    -- However if the "client_id" is present, e.g. mutateRequest to
+    -- /projects?select=client_id,name,clients(name) we would get `RETURNING
+    -- client_id, name, client_id` and then we would produce the "column
+    -- reference \"client_id\" is ambiguous" error from PostgreSQL. So we
+    -- deduplicate with Set: We are adding the primary key columns as well to
+    -- make sure, that a proper location header can always be built for
+    -- INSERT/POST
+    returnings = S.toList . S.fromList $ fldNames ++ (colName <$> fkCols) ++ pkCols
+
+-- Traditional filters(e.g. id=eq.1) are added as root nodes of the LogicTree
+-- they are later concatenated with AND in the QueryBuilder
+addFilterToLogicForest :: Filter -> [LogicTree] -> [LogicTree]
+addFilterToLogicForest flt lf = Stmnt flt : lf

src/PostgREST/Request/Parsers.hs

@@ -0,0 +1,276 @@
+{-|
+Module      : PostgREST.Request.Parsers
+Description : PostgREST parser combinators
+
+This module is in charge of parsing all the querystring values in an url, e.g. the select, id, order in `/projects?select=id,name&id=eq.1&order=id,name.desc`.
+-}
+module PostgREST.Request.Parsers
+  ( pColumns
+  , pLogicPath
+  , pLogicSingleVal
+  , pLogicTree
+  , pOrder
+  , pOrderTerm
+  , pRequestColumns
+  , pRequestFilter
+  , pRequestLogicTree
+  , pRequestOnConflict
+  , pRequestOrder
+  , pRequestRange
+  , pRequestSelect
+  , pSingleVal
+  , pTreePath
+  ) where
+
+import qualified Data.HashMap.Strict as M
+import qualified Data.Set            as S
+
+import Data.Either.Combinators       (mapLeft)
+import Data.Foldable                 (foldl1)
+import Data.List                     (init, last)
+import Data.Text                     (intercalate, replace, strip)
+import Data.Tree                     (Tree (..))
+import Text.Parsec.Error             (errorMessages,
+                                      showErrorMessages)
+import Text.ParserCombinators.Parsec (GenParser, ParseError, Parser,
+                                      anyChar, between, char, digit,
+                                      eof, errorPos, letter,
+                                      lookAhead, many1, noneOf,
+                                      notFollowedBy, oneOf, option,
+                                      optionMaybe, parse, sepBy1,
+                                      string, try, (<?>))
+
+import PostgREST.DbStructure.Identifiers (FieldName)
+import PostgREST.Error                   (ApiRequestError (ParseRequestError))
+import PostgREST.Query.SqlFragment       (ftsOperators, operators)
+import PostgREST.RangeQuery              (NonnegRange)
+
+import PostgREST.Request.Types
+
+import Protolude      hiding (intercalate, option, replace, toS, try)
+import Protolude.Conv (toS)
+
+pRequestSelect :: Text -> Either ApiRequestError [Tree SelectItem]
+pRequestSelect selStr =
+  mapError $ parse pFieldForest ("failed to parse select parameter (" <> toS selStr <> ")") (toS selStr)
+
+pRequestOnConflict :: Text -> Either ApiRequestError  [FieldName]
+pRequestOnConflict oncStr =
+  mapError $ parse pColumns ("failed to parse on_conflict parameter (" <> toS oncStr <> ")") (toS oncStr)
+
+pRequestFilter :: (Text, Text) -> Either ApiRequestError (EmbedPath, Filter)
+pRequestFilter (k, v) = mapError $ (,) <$> path <*> (Filter <$> fld <*> oper)
+  where
+    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
+    oper = parse (pOpExpr pSingleVal) ("failed to parse filter (" ++ toS v ++ ")") $ toS v
+    path = fst <$> treePath
+    fld = snd <$> treePath
+
+pRequestOrder :: (Text, Text) -> Either ApiRequestError (EmbedPath, [OrderTerm])
+pRequestOrder (k, v) = mapError $ (,) <$> path <*> ord'
+  where
+    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
+    path = fst <$> treePath
+    ord' = parse pOrder ("failed to parse order (" ++ toS v ++ ")") $ toS v
+
+pRequestRange :: (ByteString, NonnegRange) -> Either ApiRequestError (EmbedPath, NonnegRange)
+pRequestRange (k, v) = mapError $ (,) <$> path <*> pure v
+  where
+    treePath = parse pTreePath ("failed to parser tree path (" ++ toS k ++ ")") $ toS k
+    path = fst <$> treePath
+
+pRequestLogicTree :: (Text, Text) -> Either ApiRequestError (EmbedPath, LogicTree)
+pRequestLogicTree (k, v) = mapError $ (,) <$> embedPath <*> logicTree
+  where
+    path = parse pLogicPath ("failed to parser logic path (" ++ toS k ++ ")") $ toS k
+    embedPath = fst <$> path
+    logicTree = do
+      op <- snd <$> path
+      -- Concat op and v to make pLogicTree argument regular,
+      -- in the form of "?and=and(.. , ..)" instead of "?and=(.. , ..)"
+      parse pLogicTree ("failed to parse logic tree (" ++ toS v ++ ")") $ toS (op <> v)
+
+pRequestColumns :: Maybe Text -> Either ApiRequestError (Maybe (S.Set FieldName))
+pRequestColumns colStr =
+  case colStr of
+    Just str ->
+      mapError $ Just . S.fromList <$> parse pColumns ("failed to parse columns parameter (" <> toS str <> ")") (toS str)
+    _ -> Right Nothing
+
+ws :: Parser Text
+ws = toS <$> many (oneOf " \t")
+
+lexeme :: Parser a -> Parser a
+lexeme p = ws *> p <* ws
+
+pTreePath :: Parser (EmbedPath, Field)
+pTreePath = do
+  p <- pFieldName `sepBy1` pDelimiter
+  jp <- option [] pJsonPath
+  return (init p, (last p, jp))
+
+pFieldForest :: Parser [Tree SelectItem]
+pFieldForest = pFieldTree `sepBy1` lexeme (char ',')
+  where
+    pFieldTree :: Parser (Tree SelectItem)
+    pFieldTree =  try (Node <$> pRelationSelect <*> between (char '(') (char ')') pFieldForest) <|>
+                  Node <$> pFieldSelect <*> pure []
+
+pStar :: Parser Text
+pStar = toS <$> (string "*" $> ("*"::ByteString))
+
+pFieldName :: Parser Text
+pFieldName =
+  pQuotedValue <|>
+  intercalate "-" . map toS <$> (many1 (letter <|> digit <|> oneOf "_ ") `sepBy1` dash) <?>
+  "field name (* or [a..z0..9_])"
+  where
+    isDash :: GenParser Char st ()
+    isDash = try ( char '-' >> notFollowedBy (char '>') )
+    dash :: Parser Char
+    dash = isDash $> '-'
+
+pJsonPath :: Parser JsonPath
+pJsonPath = many pJsonOperation
+  where
+    pJsonOperation :: Parser JsonOperation
+    pJsonOperation = pJsonArrow <*> pJsonOperand
+
+    pJsonArrow   =
+      try (string "->>" $> J2Arrow) <|>
+      try (string "->" $> JArrow)
+
+    pJsonOperand =
+      let pJKey = JKey . toS <$> pFieldName
+          pJIdx = JIdx . toS <$> ((:) <$> option '+' (char '-') <*> many1 digit) <* pEnd
+          pEnd = try (void $ lookAhead (string "->")) <|>
+                 try (void $ lookAhead (string "::")) <|>
+                 try eof in
+      try pJIdx <|> try pJKey
+
+pField :: Parser Field
+pField = lexeme $ (,) <$> pFieldName <*> option [] pJsonPath
+
+aliasSeparator :: Parser ()
+aliasSeparator = char ':' >> notFollowedBy (char ':')
+
+pRelationSelect :: Parser SelectItem
+pRelationSelect = lexeme $ try ( do
+    alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
+    fld <- pField
+    hint <- optionMaybe (
+        try ( char '!' *> pFieldName) <|>
+        -- deprecated, remove in next major version
+        try ( char '.' *> pFieldName)
+      )
+    return (fld, Nothing, alias, hint)
+  )
+
+pFieldSelect :: Parser SelectItem
+pFieldSelect = lexeme $
+  try (
+    do
+      alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
+      fld <- pField
+      cast' <- optionMaybe (string "::" *> many letter)
+      return (fld, toS <$> cast', alias, Nothing)
+  )
+  <|> do
+    s <- pStar
+    return ((s, []), Nothing, Nothing, Nothing)
+
+pOpExpr :: Parser SingleVal -> Parser OpExpr
+pOpExpr pSVal = try ( string "not" *> pDelimiter *> (OpExpr True <$> pOperation)) <|> OpExpr False <$> pOperation
+  where
+    pOperation :: Parser Operation
+    pOperation =
+          Op . toS <$> foldl1 (<|>) (try . ((<* pDelimiter) . string) . toS <$> M.keys ops) <*> pSVal
+      <|> In <$> (try (string "in" *> pDelimiter) *> pListVal)
+      <|> pFts
+      <?> "operator (eq, gt, ...)"
+
+    pFts = do
+      op   <- foldl1 (<|>) (try . string . toS <$> ftsOps)
+      lang <- optionMaybe $ try (between (char '(') (char ')') (many (letter <|> digit <|> oneOf "_")))
+      pDelimiter >> Fts (toS op) (toS <$> lang) <$> pSVal
+
+    ops = M.filterWithKey (const . flip notElem ("in":ftsOps)) operators
+    ftsOps = M.keys ftsOperators
+
+pSingleVal :: Parser SingleVal
+pSingleVal = toS <$> many anyChar
+
+pListVal :: Parser ListVal
+pListVal = lexeme (char '(') *> pListElement `sepBy1` char ',' <* lexeme (char ')')
+
+pListElement :: Parser Text
+pListElement = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> (toS <$> many (noneOf ",)"))
+
+pQuotedValue :: Parser Text
+pQuotedValue = toS <$> (char '"' *> many (noneOf "\"") <* char '"')
+
+pDelimiter :: Parser Char
+pDelimiter = char '.' <?> "delimiter (.)"
+
+pOrder :: Parser [OrderTerm]
+pOrder = lexeme pOrderTerm `sepBy1` char ','
+
+pOrderTerm :: Parser OrderTerm
+pOrderTerm = do
+  fld <- pField
+  dir <- optionMaybe $
+         try (pDelimiter *> string "asc" $> OrderAsc) <|>
+         try (pDelimiter *> string "desc" $> OrderDesc)
+  nls <- optionMaybe pNulls <* pEnd <|>
+         pEnd $> Nothing
+  return $ OrderTerm fld dir nls
+  where
+    pNulls = try (pDelimiter *> string "nullsfirst" $> OrderNullsFirst) <|>
+             try (pDelimiter *> string "nullslast"  $> OrderNullsLast)
+    pEnd = try (void $ lookAhead (char ',')) <|>
+           try eof
+
+pLogicTree :: Parser LogicTree
+pLogicTree = Stmnt <$> try pLogicFilter
+             <|> Expr <$> pNot <*> pLogicOp <*> (lexeme (char '(') *> pLogicTree `sepBy1` lexeme (char ',') <* lexeme (char ')'))
+  where
+    pLogicFilter :: Parser Filter
+    pLogicFilter = Filter <$> pField <* pDelimiter <*> pOpExpr pLogicSingleVal
+    pNot :: Parser Bool
+    pNot = try (string "not" *> pDelimiter $> True)
+           <|> pure False
+           <?> "negation operator (not)"
+    pLogicOp :: Parser LogicOperator
+    pLogicOp = try (string "and" $> And)
+               <|> string "or" $> Or
+               <?> "logic operator (and, or)"
+
+pLogicSingleVal :: Parser SingleVal
+pLogicSingleVal = try (pQuotedValue <* notFollowedBy (noneOf ",)")) <|> try pPgArray <|> (toS <$> many (noneOf ",)"))
+  where
+    pPgArray :: Parser Text
+    pPgArray =  do
+      a <- string "{"
+      b <- many (noneOf "{}")
+      c <- string "}"
+      pure (toS $ a ++ b ++ c)
+
+pLogicPath :: Parser (EmbedPath, Text)
+pLogicPath = do
+  path <- pFieldName `sepBy1` pDelimiter
+  let op = last path
+      notOp = "not." <> op
+  return (filter (/= "not") (init path), if "not" `elem` path then notOp else op)
+
+pColumns :: Parser [FieldName]
+pColumns = pFieldName `sepBy1` lexeme (char ',')
+
+mapError :: Either ParseError a -> Either ApiRequestError a
+mapError = mapLeft translateError
+  where
+    translateError e =
+      ParseRequestError message details
+      where
+        message = show $ errorPos e
+        details = strip $ replace "\n" " " $ toS
+           $ showErrorMessages "or" "unknown parse error" "expecting" "unexpected" "end of input" (errorMessages e)

src/PostgREST/Request/Preferences.hs

@@ -0,0 +1,54 @@
+module PostgREST.Request.Preferences where
+
+import GHC.Show
+import Protolude
+
+
+data PreferResolution
+  = MergeDuplicates
+  | IgnoreDuplicates
+
+instance Show PreferResolution where
+  show MergeDuplicates  = "resolution=merge-duplicates"
+  show IgnoreDuplicates = "resolution=ignore-duplicates"
+
+-- | How to return the mutated data. From https://tools.ietf.org/html/rfc7240#section-4.2
+data PreferRepresentation
+  = Full        -- ^ Return the body plus the Location header(in case of POST).
+  | HeadersOnly -- ^ Return the Location header(in case of POST). This needs a SELECT privilege on the pk.
+  | None        -- ^ Return nothing from the mutated data.
+  deriving Eq
+
+instance Show PreferRepresentation where
+  show Full        = "return=representation"
+  show None        = "return=minimal"
+  show HeadersOnly = "return=headers-only"
+
+data PreferParameters
+  = SingleObject    -- ^ Pass all parameters as a single json object to a stored procedure
+  | MultipleObjects -- ^ Pass an array of json objects as params to a stored procedure
+  deriving Eq
+
+instance Show PreferParameters where
+  show SingleObject    = "params=single-object"
+  show MultipleObjects = "params=multiple-objects"
+
+data PreferCount
+  = ExactCount     -- ^ exact count(slower)
+  | PlannedCount   -- ^ PostgreSQL query planner rows count guess. Done by using EXPLAIN {query}.
+  | EstimatedCount -- ^ use the query planner rows if the count is superior to max-rows, otherwise get the exact count.
+  deriving Eq
+
+instance Show PreferCount where
+  show ExactCount     = "count=exact"
+  show PlannedCount   = "count=planned"
+  show EstimatedCount = "count=estimated"
+
+data PreferTransaction
+  = Commit   -- Commit transaction - the default.
+  | Rollback -- Rollback transaction after sending the response - does not persist changes, e.g. for running tests.
+  deriving Eq
+
+instance Show PreferTransaction where
+  show Commit   = "tx=commit"
+  show Rollback = "tx=rollback"

src/PostgREST/Request/Types.hs

@@ -0,0 +1,208 @@
+{-# LANGUAGE DuplicateRecordFields #-}
+module PostgREST.Request.Types
+  ( Alias
+  , Depth
+  , EmbedHint
+  , EmbedPath
+  , Field
+  , Filter(..)
+  , JoinCondition(..)
+  , JsonOperand(..)
+  , JsonOperation(..)
+  , JsonPath
+  , ListVal
+  , LogicOperator(..)
+  , LogicTree(..)
+  , MutateQuery(..)
+  , MutateRequest
+  , NodeName
+  , OpExpr(..)
+  , Operation (..)
+  , OrderDirection(..)
+  , OrderNulls(..)
+  , OrderTerm(..)
+  , ReadNode
+  , ReadQuery(..)
+  , ReadRequest
+  , SelectItem
+  , SingleVal
+  , fstFieldNames
+  ) where
+
+import qualified Data.ByteString.Lazy as BL
+import qualified Data.Set             as S
+
+import Data.Tree (Tree (..))
+
+import qualified GHC.Show (show)
+
+import PostgREST.DbStructure.Identifiers  (FieldName,
+                                           QualifiedIdentifier)
+import PostgREST.DbStructure.Relationship (Relationship)
+import PostgREST.RangeQuery               (NonnegRange)
+import PostgREST.Request.Preferences      (PreferResolution)
+
+import Protolude
+
+
+type ReadRequest = Tree ReadNode
+type MutateRequest = MutateQuery
+
+type ReadNode =
+  (ReadQuery, (NodeName, Maybe Relationship, Maybe Alias, Maybe EmbedHint, Depth))
+
+type NodeName = Text
+type Depth = Integer
+
+data ReadQuery = Select
+  { select         :: [SelectItem]
+  , from           :: QualifiedIdentifier
+  -- ^ A table alias is used in case of self joins
+  , fromAlias      :: Maybe Alias
+  -- ^ Only used for Many to Many joins. Parent and Child joins use explicit joins.
+  , implicitJoins  :: [QualifiedIdentifier]
+  , where_         :: [LogicTree]
+  , joinConditions :: [JoinCondition]
+  , order          :: [OrderTerm]
+  , range_         :: NonnegRange
+  }
+  deriving (Eq)
+
+data JoinCondition =
+  JoinCondition
+    (QualifiedIdentifier, FieldName)
+    (QualifiedIdentifier, FieldName)
+  deriving (Eq)
+
+data OrderTerm = OrderTerm
+  { otTerm      :: Field
+  , otDirection :: Maybe OrderDirection
+  , otNullOrder :: Maybe OrderNulls
+  }
+  deriving (Eq)
+
+data OrderDirection
+  = OrderAsc
+  | OrderDesc
+  deriving (Eq)
+
+instance Show OrderDirection where
+  show OrderAsc  = "ASC"
+  show OrderDesc = "DESC"
+
+data OrderNulls
+  = OrderNullsFirst
+  | OrderNullsLast
+  deriving (Eq)
+
+instance Show OrderNulls where
+  show OrderNullsFirst = "NULLS FIRST"
+  show OrderNullsLast  = "NULLS LAST"
+
+data MutateQuery
+  = Insert
+      { in_        :: QualifiedIdentifier
+      , insCols    :: S.Set FieldName
+      , insBody    :: Maybe BL.ByteString
+      , onConflict :: Maybe (PreferResolution, [FieldName])
+      , where_     :: [LogicTree]
+      , returning  :: [FieldName]
+      }
+  | Update
+      { in_       :: QualifiedIdentifier
+      , updCols   :: S.Set FieldName
+      , updBody   :: Maybe BL.ByteString
+      , where_    :: [LogicTree]
+      , returning :: [FieldName]
+      }
+  | Delete
+      { in_       :: QualifiedIdentifier
+      , where_    :: [LogicTree]
+      , returning :: [FieldName]
+      }
+
+-- | The select value in `/tbl?select=alias:field::cast`
+type SelectItem = (Field, Maybe Cast, Maybe Alias, Maybe EmbedHint)
+
+type Field = (FieldName, JsonPath)
+type Cast = Text
+type Alias = Text
+
+-- | Disambiguates an embedding operation when there's multiple relationships
+-- between two tables. Can be the name of a foreign key constraint, column
+-- name or the junction in an m2m relationship.
+type EmbedHint = Text
+
+-- | Path of the embedded levels, e.g "clients.projects.name=eq.." gives Path
+-- ["clients", "projects"]
+type EmbedPath = [Text]
+
+-- | Json path operations as specified in
+-- https://www.postgresql.org/docs/current/static/functions-json.html
+type JsonPath = [JsonOperation]
+
+-- | Represents the single arrow `->` or double arrow `->>` operators
+data JsonOperation
+  = JArrow { jOp :: JsonOperand }
+  | J2Arrow { jOp :: JsonOperand }
+  deriving (Eq)
+
+-- | Represents the key(`->'key'`) or index(`->'1`::int`), the index is Text
+-- because we reuse our escaping functons and let pg do the casting with
+-- '1'::int
+data JsonOperand
+  = JKey { jVal :: Text }
+  | JIdx { jVal :: Text }
+  deriving (Eq)
+
+-- First level FieldNames(e.g get a,b from /table?select=a,b,other(c,d))
+fstFieldNames :: ReadRequest -> [FieldName]
+fstFieldNames (Node (sel, _) _) =
+  fst . (\(f, _, _, _) -> f) <$> select sel
+
+
+-- | Boolean logic expression tree e.g. "and(name.eq.N,or(id.eq.1,id.eq.2))" is:
+--
+--            And
+--           /   \
+--  name.eq.N     Or
+--               /  \
+--         id.eq.1   id.eq.2
+data LogicTree
+  = Expr Bool LogicOperator [LogicTree]
+  | Stmnt Filter
+  deriving (Eq)
+
+data LogicOperator
+  = And
+  | Or
+  deriving Eq
+
+instance Show LogicOperator where
+  show And = "AND"
+  show Or  = "OR"
+
+data Filter = Filter
+  { field  :: Field
+  , opExpr :: OpExpr
+  }
+  deriving (Eq)
+
+data OpExpr =
+  OpExpr Bool Operation
+  deriving (Eq)
+
+data Operation
+  = Op Operator SingleVal
+  | In ListVal
+  | Fts Operator (Maybe Language) SingleVal
+  deriving (Eq)
+
+type Operator = Text
+type Language = Text
+
+-- | Represents a single value in a filter, e.g. id=eq.singleval
+type SingleVal = Text
+
+-- | Represents a list value in a filter, e.g. id=in.(val1,val2,val3)
+type ListVal = [Text]

src/PostgREST/Types.hs

@@ -1,239 +0,0 @@
-{-# LANGUAGE DuplicateRecordFields    #-}
-module PostgREST.Types where
-import           Protolude
-import qualified GHC.Show
-import           Data.Aeson
-import qualified Data.ByteString.Lazy as BL
-import qualified Data.HashMap.Strict  as M
-import           Data.Tree
-import qualified Data.Vector          as V
-import           PostgREST.RangeQuery (NonnegRange)
-import           Network.HTTP.Types.Header (hContentType, Header)
-
--- | Enumeration of currently supported response content types
-data ContentType = CTApplicationJSON | CTTextCSV | CTOpenAPI
-                 | CTSingularJSON | CTOctetStream
-                 | CTAny | CTOther ByteString deriving Eq
-
-data ApiRequestError = ActionInappropriate
-                     | InvalidBody ByteString
-                     | InvalidRange
-                     | ParseRequestError Text Text
-                     | UnknownRelation
-                     | NoRelationBetween Text Text
-                     | UnsupportedVerb
-                     deriving (Show, Eq)
-
-data DbStructure = DbStructure {
-  dbTables      :: [Table]
-, dbColumns     :: [Column]
-, dbRelations   :: [Relation]
-, dbPrimaryKeys :: [PrimaryKey]
-, dbProcs       :: M.HashMap Text ProcDescription
-} deriving (Show, Eq)
-
-data PgArg = PgArg {
-  pgaName :: Text
-, pgaType :: Text
-, pgaReq  :: Bool
-} deriving (Show, Eq)
-
-data PgType = Scalar QualifiedIdentifier | Composite QualifiedIdentifier deriving (Eq, Show)
-
-data RetType = Single PgType | SetOf PgType deriving (Eq, Show)
-
-data ProcVolatility = Volatile | Stable | Immutable
-  deriving (Eq, Show)
-
-data ProcDescription = ProcDescription {
-  pdName        :: Text
-, pdDescription :: Maybe Text
-, pdArgs        :: [PgArg]
-, pdReturnType  :: RetType
-, pdVolatility  :: ProcVolatility
-} deriving (Show, Eq)
-
-type Schema = Text
-type TableName = Text
-type SqlQuery = Text
-type SqlFragment = Text
-type RequestBody = BL.ByteString
-
-data Table = Table {
-  tableSchema      :: Schema
-, tableName        :: TableName
-, tableDescription :: Maybe Text
-, tableInsertable  :: Bool
-} deriving (Show, Ord)
-
-newtype ForeignKey = ForeignKey { fkCol :: Column } deriving (Show, Eq, Ord)
-
-data Column =
-    Column {
-      colTable       :: Table
-    , colName        :: Text
-    , colDescription :: Maybe Text
-    , colPosition    :: Int32
-    , colNullable    :: Bool
-    , colType        :: Text
-    , colUpdatable   :: Bool
-    , colMaxLen      :: Maybe Int32
-    , colPrecision   :: Maybe Int32
-    , colDefault     :: Maybe Text
-    , colEnum        :: [Text]
-    , colFK          :: Maybe ForeignKey
-    } deriving (Show, Ord)
-
-type Synonym = (Column,Column)
-
-data PrimaryKey = PrimaryKey {
-    pkTable :: Table
-  , pkName  :: Text
-} deriving (Show, Eq)
-
-data OrderDirection = OrderAsc | OrderDesc deriving (Eq)
-instance Show OrderDirection where
-  show OrderAsc  = "asc"
-  show OrderDesc = "desc"
-
-data OrderNulls = OrderNullsFirst | OrderNullsLast deriving (Eq)
-instance Show OrderNulls where
-  show OrderNullsFirst = "nulls first"
-  show OrderNullsLast  = "nulls last"
-
-data OrderTerm = OrderTerm {
-  otTerm      :: Field
-, otDirection :: Maybe OrderDirection
-, otNullOrder :: Maybe OrderNulls
-} deriving (Show, Eq)
-
-data QualifiedIdentifier = QualifiedIdentifier {
-  qiSchema :: Schema
-, qiName   :: TableName
-} deriving (Show, Eq)
-
-
-data RelationType = Child | Parent | Many | Root deriving (Show, Eq)
-
-{-|
-  The name 'Relation' here is used with the meaning
-  "What is the relation between the current node and the parent node".
-  It has nothing to do with PostgreSQL referring to tables/views as relations.
--}
-data Relation = Relation {
-  relTable    :: Table
-, relColumns  :: [Column]
-, relFTable   :: Table
-, relFColumns :: [Column]
-, relType     :: RelationType
-, relLTable   :: Maybe Table
-, relLCols1   :: Maybe [Column]
-, relLCols2   :: Maybe [Column]
-} deriving (Show, Eq)
-
--- | An array of JSON objects that has been verified to have
--- the same keys in every object
-newtype PayloadJSON = PayloadJSON (V.Vector Object)
-  deriving (Show, Eq)
-
-unPayloadJSON :: PayloadJSON -> V.Vector Object
-unPayloadJSON (PayloadJSON objs) = objs
-
-data Proxy = Proxy {
-  proxyScheme     :: Text
-, proxyHost       :: Text
-, proxyPort       :: Integer
-, proxyPath       :: Text
-} deriving (Show, Eq)
-
-type Operator = Text
-operators :: M.HashMap Operator SqlFragment
-operators = M.fromList [
-  ("eq", "="),
-  ("gte", ">="),
-  ("gt", ">"),
-  ("lte", "<="),
-  ("lt", "<"),
-  ("neq", "<>"),
-  ("like", "LIKE"),
-  ("ilike", "ILIKE"),
-  ("in", "IN"),
-  ("notin", "NOT IN"),
-  ("isnot", "IS NOT"),
-  ("is", "IS"),
-  ("fts", "@@"),
-  ("cs", "@>"),
-  ("cd", "<@"),
-  ("ov", "&&"),
-  ("sl", "<<"),
-  ("sr", ">>"),
-  ("nxr", "&<"),
-  ("nxl", "&>"),
-  ("adj", "-|-"),
-  -- TODO: these are deprecated and should be removed in v0.5.0.0
-  ("@@", "@@"),
-  ("@>", "@>"),
-  ("<@", "<@")]
-data Operation = Operation{ hasNot::Bool, expr::(Operator, Operand) } deriving (Eq, Show)
-data Operand = VText Text | VTextL [Text] | VForeignKey QualifiedIdentifier ForeignKey deriving (Show, Eq)
-
-data LogicOperator = And | Or deriving Eq
-instance Show LogicOperator where
-  show And  = "AND"
-  show Or = "OR"
-{-|
-  Boolean logic expression tree e.g. "and(name.eq.N,or(id.eq.1,id.eq.2))" is:
-
-            And
-           /   \
-  name.eq.N     Or
-               /  \
-         id.eq.1   id.eq.2
--}
-data LogicTree = Expr Bool LogicOperator [LogicTree] | Stmnt Filter deriving (Show, Eq)
-
-type FieldName = Text
-type JsonPath = [Text]
-type Field = (FieldName, Maybe JsonPath)
-type Alias = Text
-type Cast = Text
-type NodeName = Text
-
-{-|
-  This type will hold information about which particular 'Relation' between two tables to choose when there are multiple ones.
-  Specifically, it will contain the name of the foreign key or the join table in many to many relations.
--}
-type RelationDetail = Text
-type SelectItem = (Field, Maybe Cast, Maybe Alias, Maybe RelationDetail)
--- | Path of the embedded levels, e.g "clients.projects.name=eq.." gives Path ["clients", "projects"]
-type EmbedPath = [Text]
-data Filter = Filter { field::Field, operation::Operation } deriving (Show, Eq)
-
-data ReadQuery = Select { select::[SelectItem], from::[TableName], where_::[LogicTree], order::Maybe [OrderTerm], range_::NonnegRange } deriving (Show, Eq)
-data MutateQuery = Insert { in_::TableName, qPayload::PayloadJSON, returning::[FieldName] }
-                 | Delete { in_::TableName, where_::[LogicTree], returning::[FieldName] }
-                 | Update { in_::TableName, qPayload::PayloadJSON, where_::[LogicTree], returning::[FieldName] } deriving (Show, Eq)
-type ReadNode = (ReadQuery, (NodeName, Maybe Relation, Maybe Alias, Maybe RelationDetail))
-type ReadRequest = Tree ReadNode
-type MutateRequest = MutateQuery
-data DbRequest = DbRead ReadRequest | DbMutate MutateRequest
-
-instance Eq Table where
-  Table{tableSchema=s1,tableName=n1} == Table{tableSchema=s2,tableName=n2} = s1 == s2 && n1 == n2
-
-instance Eq Column where
-  Column{colTable=t1,colName=n1} == Column{colTable=t2,colName=n2} = t1 == t2 && n1 == n2
-
--- | Convert from ContentType to a full HTTP Header
-toHeader :: ContentType -> Header
-toHeader ct = (hContentType, toMime ct <> "; charset=utf-8")
-
--- | Convert from ContentType to a ByteString representing the mime type
-toMime :: ContentType -> ByteString
-toMime CTApplicationJSON = "application/json"
-toMime CTTextCSV         = "text/csv"
-toMime CTOpenAPI         = "application/openapi+json"
-toMime CTSingularJSON    = "application/vnd.pgrst.object+json"
-toMime CTOctetStream     = "application/octet-stream"
-toMime CTAny             = "*/*"
-toMime (CTOther ct)      = ct

src/PostgREST/Unix.hs

@@ -0,0 +1,59 @@
+module PostgREST.Unix
+  ( runAppWithSocket
+  , installSignalHandlers
+  ) where
+
+import qualified Network.Socket           as Socket
+import qualified Network.Wai.Handler.Warp as Warp
+import qualified System.Posix.Signals     as Signals
+
+import Network.Wai        (Application)
+import System.Directory   (removeFile)
+import System.IO.Error    (isDoesNotExistError)
+import System.Posix.Files (setFileMode)
+import System.Posix.Types (FileMode)
+
+import qualified PostgREST.AppState as AppState
+import qualified PostgREST.Workers  as Workers
+
+import Protolude
+
+
+-- | Run the PostgREST application with user defined socket.
+runAppWithSocket :: Warp.Settings -> Application -> FileMode -> FilePath -> IO ()
+runAppWithSocket settings app socketFileMode socketFilePath =
+  bracket createAndBindSocket Socket.close $ \socket -> do
+    Socket.listen socket Socket.maxListenQueue
+    Warp.runSettingsSocket settings socket app
+  where
+    createAndBindSocket = do
+      deleteSocketFileIfExist socketFilePath
+      sock <- Socket.socket Socket.AF_UNIX Socket.Stream Socket.defaultProtocol
+      Socket.bind sock $ Socket.SockAddrUnix socketFilePath
+      setFileMode socketFilePath socketFileMode
+      return sock
+
+    deleteSocketFileIfExist path =
+      removeFile path `catch` handleDoesNotExist
+
+    handleDoesNotExist e
+      | isDoesNotExistError e = return ()
+      | otherwise = throwIO e
+
+-- | Set signal handlers, only for systems with signals
+installSignalHandlers :: AppState.AppState -> IO ()
+installSignalHandlers appState = do
+  -- Releases the connection pool whenever the program is terminated,
+  -- see https://github.com/PostgREST/postgrest/issues/268
+  install Signals.sigINT $ AppState.releasePool appState
+  install Signals.sigTERM $ AppState.releasePool appState
+
+  -- The SIGUSR1 signal updates the internal 'DbStructure' by running
+  -- 'connectionWorker' exactly as before.
+  install Signals.sigUSR1 $ Workers.connectionWorker appState
+
+  -- Re-read the config on SIGUSR2
+  install Signals.sigUSR2 $ Workers.reReadConfig False appState
+  where
+    install signal handler =
+      void $ Signals.installHandler signal (Signals.Catch handler) Nothing

src/PostgREST/Version.hs

@@ -0,0 +1,29 @@
+{-# LANGUAGE TemplateHaskell #-}
+{-# OPTIONS_GHC -fno-warn-type-defaults #-}
+module PostgREST.Version
+  ( docsVersion
+  , prettyVersion
+  ) where
+
+import qualified Data.Text as T
+
+import Data.Version       (versionBranch)
+import Development.GitRev (gitHash)
+import Paths_postgrest    (version)
+
+import Protolude
+
+
+-- | User friendly version number
+prettyVersion :: Text
+prettyVersion =
+  T.intercalate "." (map show $ versionBranch version) <> gitRev
+  where
+    gitRev =
+      if $(gitHash) == "UNKNOWN"
+        then mempty
+        else " (" <> T.take 7 $(gitHash) <> ")"
+
+-- | Version number used in docs
+docsVersion :: Text
+docsVersion = "v" <> T.dropEnd 1 (T.dropWhileEnd (/= '.') prettyVersion)