chore: run doctests in parallel

Runs the doctests much faster, which is potentially useful in
combination with postgrest-watch for local development.

This implies that doctests run on compiled code, not in a GHCi session,
which has some implications:
- Only exported functions can be tested.
- Imports need to be made explicit in doctests themselves.

On the flipside, this would allow us to potentially include doctest
results in code coverage, I believe.

This change is a requirement to vendor hasql, which otherwise breaks the
existing doctests: hasql contains a .hsc file, which *needs* to be
compiled - not interpreted - to make the tests work.

.github/workflows/test.yaml

@@ -63,7 +63,7 @@ jobs:
 
       - name: Run doctests
         if: always()
-        run: postgrest-test-doctests
+        run: nix-shell --run postgrest-test-doctests
 
       - name: Check the spec tests for idempotence
         if: always()

.gitignore

@@ -30,3 +30,4 @@ gen_private.json
 .pytest_cache
 .ruff_cache
 postgrest-module-graph.png
+.ghc.environment.*

cabal.project

@@ -2,3 +2,6 @@ packages: postgrest.cabal
 tests: true
 allow-newer:
   hasql:postgresql-libpq
+
+-- https://github.com/martijnbastiaan/doctest-parallel/blob/main/example/README.md#cabalproject
+write-ghc-environment-files: always

nix/tools/tests.nix

@@ -55,8 +55,6 @@ let
         withEnv = postgrest.env;
       }
       ''
-        # This makes nix-env -iA tests.doctests.bin work.
-        export NIX_GHC=${postgrest.env.NIX_GHC}
         ${cabal-install}/bin/cabal v2-run ${devCabalOptions} test:doctests
       '';
 

postgrest.cabal

@@ -352,14 +352,11 @@ test-suite observability
 test-suite doctests
   type:               exitcode-stdio-1.0
   default-language:   Haskell2010
-  default-extensions: OverloadedStrings
-                      NoImplicitPrelude
   hs-source-dirs:     test/doc
   main-is:            Main.hs
   build-depends:      base              >= 4.9 && < 4.22
-                    , doctest           >= 0.8
+                    , doctest-parallel  >= 0.4
                     , postgrest
                     , pretty-simple
-                    , protolude         >= 0.3.1 && < 0.4
   ghc-options:        -threaded -O0 -Werror -Wall -fwarn-identities
                       -fno-spec-constr -optP-Wno-nonportable-include-path

src/PostgREST/ApiRequest/Preferences.hs

@@ -21,6 +21,7 @@ module PostgREST.ApiRequest.Preferences
   , shouldCount
   , shouldExplainCount
   , prefAppliedHeader
+  , toHeaderValue
   ) where
 
 import qualified Data.ByteString.Char8     as BS
@@ -34,7 +35,10 @@ import Protolude
 
 -- $setup
 -- Setup for doctests
+-- >>> :set -XStandaloneDeriving
 -- >>> import Text.Pretty.Simple (pPrint)
+-- >>> import qualified Data.Set as S
+-- >>> import Protolude
 -- >>> deriving instance Show PreferResolution
 -- >>> deriving instance Show PreferRepresentation
 -- >>> deriving instance Show PreferCount

src/PostgREST/ApiRequest/QueryParams.hs

@@ -9,7 +9,18 @@
 module PostgREST.ApiRequest.QueryParams
   ( parse
   , QueryParams(..)
+  , pFieldForest
+  , pFieldName
+  , pFieldSelect
+  , pJsonPath
+  , pLogicTree
+  , pOpExpr
+  , pOrder
+  , pRelationSelect
+  , pRequestFilter
   , pRequestRange
+  , pSingleVal
+  , pSpreadRelationSelect
   ) where
 
 import qualified Data.ByteString.Char8         as BS
@@ -62,6 +73,10 @@ import PostgREST.Error (QPError (..))
 
 import Protolude hiding (Sum, try)
 
+-- $setup
+-- >>> import qualified Text.ParserCombinators.Parsec as P
+-- >>> import Protolude hiding (Sum, try)
+
 data QueryParams =
   QueryParams
     { qsCanonical      :: ByteString

src/PostgREST/Config.hs

@@ -597,6 +597,7 @@ pgConnString conn | uriDesignator `T.isPrefixOf` conn || shortUriDesignator `T.i
 
 -- | Adds a `fallback_application_name` value to the connection string. This allows querying the PostgREST version on pg_stat_activity.
 --
+-- >>> import Protolude
 -- >>> let ver = "11.1.0 (5a04ec7)"::ByteString
 -- >>> let strangeVer = "11'1&0@#$%,.:\"[]{}?+^()=asdfqwer"::ByteString
 --

src/PostgREST/Error.hs

@@ -19,6 +19,8 @@ module PostgREST.Error
   , JwtClaimsError(..)
   , errorPayload
   , status
+  , noRelBetweenHint
+  , noRpcHint
   ) where
 
 import qualified Data.Aeson                as JSON
@@ -57,6 +59,12 @@ import PostgREST.Error.Types
 
 import Protolude
 
+-- $setup
+-- >>> import qualified Data.HashMap.Strict as HM
+-- >>> import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..))
+-- >>> import PostgREST.SchemaCache.Relationship (Relationship (..))
+-- >>> import PostgREST.SchemaCache.Routine (Routine (..), RoutineParam (..))
+
 -- | Encode Error to ByteString
 errorPayload :: (ErrorBody a, ErrorHeaders a) => Verbosity -> a -> LByteString
 errorPayload verb = JSON.encode . toJsonPgrstError verb

src/PostgREST/MediaType.hs

@@ -9,6 +9,7 @@ module PostgREST.MediaType
   , toContentType
   , toMime
   , decodeMediaType
+  , tokenizeMediaType
   ) where
 
 import qualified Data.Aeson                    as JSON
@@ -22,6 +23,9 @@ import Network.HTTP.Types.Header (Header, hContentType)
 
 import Protolude
 
+-- $setup
+-- >>> import qualified Text.ParserCombinators.Parsec as P
+
 -- | Enumeration of currently supported media types
 data MediaType
   = MTApplicationJSON

src/PostgREST/Plan.hs

@@ -24,6 +24,7 @@ module PostgREST.Plan
   , InfoPlan(..)
   , CrudPlan(..)
   , legacyWarnings
+  , addNullEmbedFilters
   ) where
 
 import qualified Data.HashMap.Strict           as HM
@@ -87,7 +88,16 @@ import Protolude hiding (from)
 
 -- $setup
 -- Setup for doctests
+-- >>> :set -XDuplicateRecordFields
 -- >>> import Data.Ranged.Ranges (fullRange)
+-- >>> import Data.Tree (Tree (..))
+-- >>> import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..))
+-- >>> import PostgREST.ApiRequest.Types
+-- >>> import PostgREST.Plan.CallPlan
+-- >>> import PostgREST.Plan.MutatePlan
+-- >>> import PostgREST.Plan.ReadPlan as ReadPlan
+-- >>> import PostgREST.Plan.Types
+-- >>> import Protolude
 
 -- Plan for reading or writing to the db
 data CrudPlan

src/PostgREST/Response/Performance.hs

@@ -8,6 +8,9 @@ import qualified Network.HTTP.Types    as HTTP
 import           Numeric               (showFFloat)
 import           Protolude
 
+-- $setup
+-- >>> import Protolude
+
 -- | ServerTiming represents the timing data for a request, in seconds.
 data ServerTiming =
   ServerTiming

test/doc/Main.hs

@@ -1,27 +1,7 @@
-module Main (main) where
-
-import Test.DocTest (doctest)
-
-import Protolude
+module Main where
 
+import System.Environment (getArgs)
+import Test.DocTest       (mainFromCabal)
 
 main :: IO ()
-main =
-  doctest
-    [ "-XOverloadedStrings"
-    , "-XNoImplicitPrelude"
-    , "-XStandaloneDeriving"
-    , "-XDuplicateRecordFields"
-    , "-isrc"
-    , "src/PostgREST/ApiRequest/Preferences.hs"
-    , "src/PostgREST/ApiRequest/QueryParams.hs"
-    , "src/PostgREST/Config.hs"
-    , "src/PostgREST/Error.hs"
-    , "src/PostgREST/MediaType.hs"
-    , "src/PostgREST/Network.hs"
-    , "src/PostgREST/Plan.hs"
-    , "src/PostgREST/Query/SqlFragment.hs"
-    , "src/PostgREST/Response.hs"
-    , "src/PostgREST/Response/Performance.hs"
-    , "src/PostgREST/SchemaCache/Identifiers.hs"
-    ]
+main = mainFromCabal "postgrest" =<< getArgs