Fix M2M resource embedding on RPC and mutations

CHANGELOG.md

@@ -9,7 +9,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 - #1383, Add support for HEAD request - @steve-chavez
 - #1378, Add support for `Prefer: count=planned` and `Prefer: count=estimated` on GET /table - @steve-chavez
-- #1301, Allow self join resource embedding on PATCH - @herulume, @steve-chavez
+- #1301, Fix self join resource embedding on PATCH - @herulume, @steve-chavez
+- #1389, Fix many to many resource embedding on RPC/PATCH - @steve-chavez
 
 ### Changed
 

src/PostgREST/DbRequestBuilder.hs

@@ -336,9 +336,13 @@ returningCols rr@(Node _ forest) = returnings
     -- `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`.
+    -- This also works for the other relType's.
     fkCols = concat $ mapMaybe (\case
-        Node (_, (_, Just Relation{relFColumns=cols, relType=Parent}, _, _, _)) _ -> Just cols
-        Node (_, (_, Just Relation{relFColumns=cols, relType=Child}, _, _, _)) _  -> Just cols
+        Node (_, (_, Just Relation{relFColumns=cols, relType=relTyp}, _, _, _)) _ -> case relTyp of
+          Parent -> Just cols
+          Child  -> Just cols
+          Many   -> Just cols
+          _      -> Nothing
         _ -> Nothing
       ) forest
     -- However if the "client_id" is present, e.g. mutateRequest to /projects?select=client_id,name,clients(name)

src/PostgREST/QueryBuilder/Private.hs

@@ -150,9 +150,9 @@ pgFmtFilter table (Filter fld (OpExpr hasNot oper)) = notOp <> " " <> case oper
      (find ((==) . toLower $ v) ["null","true","false"])
 
 pgFmtJoinCondition :: JoinCondition -> SqlFragment
-pgFmtJoinCondition (JoinCondition (qi, col1) (QualifiedIdentifier schema fTable, col2)) =
-  pgFmtColumn qi col1 <> " = " <>
-  pgFmtColumn (removeSourceCTESchema schema fTable) col2
+pgFmtJoinCondition (JoinCondition (QualifiedIdentifier schema1 tName, col1) (QualifiedIdentifier schema2 ftName, col2)) =
+  pgFmtColumn (removeSourceCTESchema schema1 tName) col1 <> " = " <>
+  pgFmtColumn (removeSourceCTESchema schema2 ftName) col2
 
 pgFmtLogicTree :: QualifiedIdentifier -> LogicTree -> SqlFragment
 pgFmtLogicTree qi (Expr hasNot op forest) = notOp <> " (" <> intercalate (" " <> show op <> " ") (pgFmtLogicTree qi <$> forest) <> ")"
@@ -183,8 +183,11 @@ pgFmtAs _ _ (Just alias) = " AS " <> pgFmtIdent alias
 trimNullChars :: Text -> Text
 trimNullChars = T.takeWhile (/= '\x0')
 
+-- 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 == sourceCTEName then "" else schema) tbl
+removeSourceCTESchema schema tbl = QualifiedIdentifier (if tbl == sourceCTEName then mempty else schema) tbl
 
 countF :: SqlQuery -> Bool -> (SqlFragment, SqlFragment)
 countF countQuery shouldCount =

test/Feature/InsertSpec.hs

@@ -644,3 +644,23 @@ spec actualPgVersion = do
         { matchStatus  = 200,
           matchHeaders = [matchContentTypeJson]
         }
+
+    it "embeds an M2M relationship plus parent after update" $
+      request methodPatch "/users?id=eq.1&select=name,tasks(name,project:projects(name))"
+              [("Prefer", "return=representation")]
+        [json|{"name": "Kevin Malone"}|]
+        `shouldRespondWith`
+        [json|[
+          {
+            "name": "Kevin Malone",
+            "tasks": [
+                { "name": "Design w7", "project": { "name": "Windows 7" } },
+                { "name": "Code w7", "project": { "name": "Windows 7" } },
+                { "name": "Design w10", "project": { "name": "Windows 10" } },
+                { "name": "Code w10", "project": { "name": "Windows 10" } }
+            ]
+          }
+        ]|]
+        { matchStatus  = 200,
+          matchHeaders = [matchContentTypeJson]
+        }

test/Feature/RpcSpec.hs

@@ -179,6 +179,29 @@ spec actualPgVersion =
           `shouldRespondWith` [json|[{"id": 2, "articleStars": [{"userId": 3}]}]|]
           { matchHeaders = [matchContentTypeJson] }
 
+      it "can embed an M2M relationship table" $
+        get "/rpc/getallusers?select=name,tasks(name)&id=gt.1"
+          `shouldRespondWith` [json|[
+            {"name":"Michael Scott", "tasks":[{"name":"Design IOS"}, {"name":"Code IOS"}, {"name":"Design OSX"}]},
+            {"name":"Dwight Schrute","tasks":[{"name":"Design w7"}, {"name":"Design IOS"}]}
+          ]|]
+          { matchHeaders = [matchContentTypeJson] }
+
+      it "can embed an M2M relationship table that has a parent relationship table" $
+        get "/rpc/getallusers?select=name,tasks(name,project:projects(name))&id=gt.1"
+          `shouldRespondWith` [json|[
+            {"name":"Michael Scott","tasks":[
+              {"name":"Design IOS","project":{"name":"IOS"}},
+              {"name":"Code IOS","project":{"name":"IOS"}},
+              {"name":"Design OSX","project":{"name":"OSX"}}
+            ]},
+            {"name":"Dwight Schrute","tasks":[
+              {"name":"Design w7","project":{"name":"Windows 7"}},
+              {"name":"Design IOS","project":{"name":"IOS"}}
+            ]}
+          ]|]
+          { matchHeaders = [matchContentTypeJson] }
+
     context "a proc that returns an empty rowset" $
       it "returns empty json array" $ do
         post "/rpc/test_empty_rowset" [json| {} |] `shouldRespondWith`

test/fixtures/schema.sql

@@ -1749,3 +1749,7 @@ CREATE TABLE web_content (
   p_web_id integer references web_content(id),
   primary key (id)
 );
+
+CREATE FUNCTION getallusers() RETURNS SETOF users AS $$
+  SELECT * FROM test.users;
+$$ LANGUAGE sql;