From 81501aefa00f3d1b81f5c9fd31c55bce2e1407b3 Mon Sep 17 00:00:00 2001
From: Laurence Isla <lau.isla.c@gmail.com>
Date: Fri, 20 Jan 2023 09:37:15 -0500
Subject: [PATCH] fix: FK pointing to VIEW instead of TABLE in OpenAPI output

---
 src/PostgREST/Response/OpenAPI.hs        |  5 ++++-
 test/spec/Feature/OpenApi/OpenApiSpec.hs | 17 +++++++++++++++++
 test/spec/fixtures/schema.sql            | 10 ++++++++++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/PostgREST/Response/OpenAPI.hs b/src/PostgREST/Response/OpenAPI.hs
index 240551e54..adcf2b9cc 100644
--- a/src/PostgREST/Response/OpenAPI.hs
+++ b/src/PostgREST/Response/OpenAPI.hs
@@ -103,11 +103,14 @@ makeProperty tbl rels col = (colName col, Inline s)
     fk :: Maybe Text
     fk =
       let
+        searchedRels = fromMaybe mempty $ HM.lookup (QualifiedIdentifier (tableSchema tbl) (tableName tbl), tableSchema tbl) rels
+        -- Sorts the relationship list to get tables first
+        relsSortedByIsView = sortOn relFTableIsView [ r | r@Relationship{} <- searchedRels]
         -- Finds the relationship that has a single column foreign key
         rel = find (\case
           Relationship{relCardinality=(M2O _ relColumns)} -> [colName col] == (fst <$> relColumns)
           _                                               -> False
-          ) $ fromMaybe mempty $ HM.lookup (QualifiedIdentifier (tableSchema tbl) (tableName tbl), tableSchema tbl) rels
+          ) relsSortedByIsView
         fCol = (headMay . (\r -> snd <$> relColumns (relCardinality r)) =<< rel)
         fTbl = qiName . relForeignTable <$> rel
         fTblCol = (,) <$> fTbl <*> fCol
diff --git a/test/spec/Feature/OpenApi/OpenApiSpec.hs b/test/spec/Feature/OpenApi/OpenApiSpec.hs
index b7603b111..761ce6d48 100644
--- a/test/spec/Feature/OpenApi/OpenApiSpec.hs
+++ b/test/spec/Feature/OpenApi/OpenApiSpec.hs
@@ -310,6 +310,23 @@ spec actualPgVersion = describe "OpenAPI" $ do
             }
           |]
 
+  describe "VIEW created for a TABLE with a O2M relationship" $ do
+
+    it "fk points to destination TABLE instead of the VIEW" $ do
+      r <- simpleBody <$> get "/"
+
+      let referralLink = r ^? key "definitions" . key "projects" . key "properties" . key "client_id"
+
+      liftIO $
+        referralLink `shouldBe` Just
+          [aesonQQ|
+            {
+              "format": "integer",
+              "type": "integer",
+              "description": "Note:\nThis is a Foreign Key to `clients.id`.<fk table='clients' column='id'/>"
+            }
+          |]
+
   describe "PostgreSQL to Swagger Type Mapping" $ do
 
     it "character varying to string" $ do
diff --git a/test/spec/fixtures/schema.sql b/test/spec/fixtures/schema.sql
index e3a42617c..4d2412004 100644
--- a/test/spec/fixtures/schema.sql
+++ b/test/spec/fixtures/schema.sql
@@ -3076,3 +3076,13 @@ LANGUAGE sql
 AS $$
   select * from test.yards;
 $$;
+
+-- view's name is alphabetically before projects
+create view test.alpha_projects as
+  select c.id, p.name as pro_name, c.name as cli_name
+  from projects p join clients c on p.client_id = c.id;
+
+-- view's name is alphabetically after projects
+create view test.zeta_projects as
+  select c.id, p.name as pro_name, c.name as cli_name
+  from projects p join clients c on p.client_id = c.id;
\ No newline at end of file