From 80f763448f9f84a7b783af79c05ddb92265fb31c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Steve=20Ch=C3=A1vez?= <stevechavezast@gmail.com>
Date: Wed, 16 Oct 2019 12:45:38 -0500
Subject: [PATCH] Fix unique foreign key in view (#1395)

---
 CHANGELOG.md                  |  1 +
 src/PostgREST/DbStructure.hs  |  4 ++--
 test/Feature/QuerySpec.hs     |  9 +++++++++
 test/Feature/StructureSpec.hs | 17 +++++++++++++++++
 test/fixtures/data.sql        |  8 ++++++++
 test/fixtures/privileges.sql  |  2 ++
 test/fixtures/schema.sql      | 14 ++++++++++++++
 7 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 729577d2e..293bf6a1d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - #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
 
diff --git a/src/PostgREST/DbStructure.hs b/src/PostgREST/DbStructure.hs
index e459eccd9..30f0c52d2 100644
--- a/src/PostgREST/DbStructure.hs
+++ b/src/PostgREST/DbStructure.hs
@@ -393,7 +393,7 @@ allColumns tabs =
         array_to_string(enum_info.vals, ',') AS enum
     FROM (
         /*
-        -- CTE based on pg_catalog to get only Primary and Foreign key columns outside api schema
+        -- CTE based on pg_catalog to get PRIMARY/FOREIGN key and UNIQUE columns outside api schema
         */
         WITH key_columns AS (
              SELECT
@@ -409,7 +409,7 @@ allColumns tabs =
                pg_catalog.pg_class c,
                pg_catalog.pg_namespace n
              WHERE
-               r.contype IN ('f', 'p')
+               r.contype IN ('f', 'p', 'u')
                AND c.relkind IN ('r', 'v', 'f', 'm')
                AND r.conrelid = c.oid
                AND c.relnamespace = n.oid
diff --git a/test/Feature/QuerySpec.hs b/test/Feature/QuerySpec.hs
index 7e9cbddf5..3bde32795 100644
--- a/test/Feature/QuerySpec.hs
+++ b/test/Feature/QuerySpec.hs
@@ -1112,3 +1112,12 @@ spec actualPgVersion = do
 
   it "cannot use ltree(in public schema) extension operators if no extra search path added" $
     get "/ltree_sample?path=cd.Top.Science.Astronomy" `shouldRespondWith` 400
+
+  context "VIEW that has a source FK based on a UNIQUE key" $
+    it "can be embedded" $
+      get "/referrals?select=site,link:pages(url)" `shouldRespondWith`
+        [json| [
+         {"site":"github.com",     "link":{"url":"http://postgrest.org/en/v6.0/api.html"}},
+         {"site":"hub.docker.com", "link":{"url":"http://postgrest.org/en/v6.0/admin.html"}}
+        ]|]
+        { matchHeaders = [matchContentTypeJson] }
diff --git a/test/Feature/StructureSpec.hs b/test/Feature/StructureSpec.hs
index c84185205..3825aabab 100644
--- a/test/Feature/StructureSpec.hs
+++ b/test/Feature/StructureSpec.hs
@@ -231,6 +231,23 @@ spec = do
               ]
             |]
 
+    describe "VIEW that has a source FK based on a UNIQUE key" $
+
+      it "includes fk description" $ do
+        r <- simpleBody <$> get "/"
+
+        let referralLink = r ^? key "definitions" . key "referrals" . key "properties" . key "link"
+
+        liftIO $
+          referralLink `shouldBe` Just
+            [aesonQQ|
+              {
+                "format": "integer",
+                "type": "integer",
+                "description": "Note:\nThis is a Foreign Key to `pages.link`.<fk table='pages' column='link'/>"
+              }
+            |]
+
     describe "PostgreSQL to Swagger Type Mapping" $ do
 
       it "character varying to string" $ do
diff --git a/test/fixtures/data.sql b/test/fixtures/data.sql
index ccca05a95..0cfa282e4 100644
--- a/test/fixtures/data.sql
+++ b/test/fixtures/data.sql
@@ -512,3 +512,11 @@ TRUNCATE TABLE app_users CASCADE;
 INSERT INTO app_users (id, email, "password") VALUES (1, 'test@123.com','pass');
 INSERT INTO app_users (id, email, "password") VALUES (2, 'abc@123.com','pass');
 INSERT INTO app_users (id, email, "password") VALUES (3, 'def@123.com','pass');
+
+TRUNCATE TABLE private.pages CASCADE;
+INSERT INTO private.pages VALUES (1, 'http://postgrest.org/en/v6.0/api.html');
+INSERT INTO private.pages VALUES (2, 'http://postgrest.org/en/v6.0/admin.html');
+
+TRUNCATE TABLE private.referrals CASCADE;
+INSERT INTO private.referrals VALUES ('github.com', 1);
+INSERT INTO private.referrals VALUES ('hub.docker.com', 2);
diff --git a/test/fixtures/privileges.sql b/test/fixtures/privileges.sql
index 3aeb05f72..cff2f6da3 100644
--- a/test/fixtures/privileges.sql
+++ b/test/fixtures/privileges.sql
@@ -104,6 +104,8 @@ GRANT ALL ON TABLE
     , getallprojects_view
     , get_projects_above_view
     , web_content
+    , pages
+    , referrals
 TO postgrest_test_anonymous;
 
 GRANT INSERT ON TABLE insertonly TO postgrest_test_anonymous;
diff --git a/test/fixtures/schema.sql b/test/fixtures/schema.sql
index 5ec6d565a..1a7d7deb5 100755
--- a/test/fixtures/schema.sql
+++ b/test/fixtures/schema.sql
@@ -1759,3 +1759,17 @@ create table app_users (
   email    text       unique not null,
   password text       not null
 );
+
+create table private.pages (
+  link int not null unique
+, url text
+);
+
+create table private.referrals (
+  site text
+, link int references private.pages(link) not null
+);
+
+create view test.pages as select * from private.pages;
+
+create view test.referrals as select * from private.referrals;