Update with empty json (#852)

test/Feature/InsertSpec.hs

@@ -413,6 +413,30 @@ spec = do
           [json| { id: 99 } |]
           `shouldRespondWith` [json| [{id:99}] |]
           { matchHeaders = [matchContentTypeJson] }
+        -- put value back for other tests
+        void $ request methodPatch "/items?id=eq.99" [] [json| { "id":1 } |]
+
+      it "makes no updates and returns 204, when patching with an empty json object" $ do
+        request methodPatch "/items" [] [json| {} |]
+          `shouldRespondWith` ""
+          {
+            matchStatus  = 204,
+            matchHeaders = ["Content-Range" <:> "*/*"]
+          }
+
+        g <- get "/items"
+        liftIO $ simpleBody g `shouldBe` [json| [{"id":3},{"id":4},{"id":5},{"id":6},{"id":7},{"id":8},{"id":9},{"id":10},{"id":11},{"id":12},{"id":13},{"id":14},{"id":15},{id:16},{"id":2},{"id":1}] |]
+
+      it "makes no updates and and returns 200, when patching with an empty json object and return=rep" $ do
+        request methodPatch "/items" [("Prefer", "return=representation")] [json| {} |]
+          `shouldRespondWith` "[]"
+          {
+            matchStatus  = 200,
+            matchHeaders = ["Content-Range" <:> "*/*"]
+          }
+
+        g <- get "/items"
+        liftIO $ simpleBody g `shouldBe` [json| [{"id":3},{"id":4},{"id":5},{"id":6},{"id":7},{"id":8},{"id":9},{"id":10},{"id":11},{"id":12},{"id":13},{"id":14},{"id":15},{id:16},{"id":2},{"id":1}] |]
 
     context "with unicode values" $
       it "succeeds and returns values intact" $ do