fix: OpenAPI now tags a FK correctly on O2O relationships

CHANGELOG.md

@@ -13,6 +13,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - #3160, Fix using select= query parameter for custom media type handlers - @wolfgangwalther
  - #3361, Clarify PGRST204(column not found) error message - @steve-chavez
  - #3373, Remove rejected mediatype `application/vnd.pgrst.object+json` from response - @taimoorzaeem
+ - #3418, Fix OpenAPI not tagging a FK column correctly on O2O relationships - @laurenceisla
 
 ## [12.0.2] - 2023-12-20
 

src/PostgREST/Response/OpenAPI.hs

@@ -115,6 +115,7 @@ makeProperty tbl rels col = (colName col, Inline s)
         -- Finds the relationship that has a single column foreign key
         rel = find (\case
           Relationship{relCardinality=(M2O _ relColumns)} -> [colName col] == (fst <$> relColumns)
+          Relationship{relCardinality=(O2O _ relColumns)} -> [colName col] == (fst <$> relColumns)
           _                                               -> False
           ) relsSortedByIsView
         fCol = (headMay . (\r -> snd <$> relColumns (relCardinality r)) =<< rel)

test/spec/Feature/OpenApi/OpenApiSpec.hs

@@ -222,6 +222,21 @@ spec actualPgVersion = describe "OpenAPI" $ do
                     . nth 0
       liftIO $ tableTag `shouldBe` Just [aesonQQ|"authors_only"|]
 
+    it "includes a fk description for a O2O relationship" $ do
+      r <- simpleBody <$> get "/"
+
+      let referralLink = r ^? key "definitions" . key "first" . key "properties" . key "second_id_1"
+
+      liftIO $
+        referralLink `shouldBe` Just
+          [aesonQQ|
+            {
+              "format": "integer",
+              "type": "integer",
+              "description": "Note:\nThis is a Foreign Key to `second.id`.<fk table='second' column='id'/>"
+            }
+          |]
+
   describe "Foreign table" $
 
     it "includes foreign table properties" $ do