Merge selection sets

tests/Language/GraphQL/ExecuteSpec.hs

@@ -22,21 +22,54 @@ schema = Schema {query = queryType, mutation = Nothing}
 
 queryType :: Out.ObjectType Identity
 queryType = Out.ObjectType "Query" Nothing []
-    $ HashMap.singleton "count"
-    $ Out.Resolver countField
+    $ HashMap.singleton "philosopher"
+    $ Out.Resolver philosopherField
     $ pure
-    $ Int 8
+    $ Object mempty
   where
-    countField = Out.Field Nothing (Out.NonNullScalarType int) HashMap.empty
+    philosopherField =
+        Out.Field Nothing (Out.NonNullObjectType philosopherType) HashMap.empty
+
+philosopherType :: Out.ObjectType Identity
+philosopherType = Out.ObjectType "Philosopher" Nothing []
+    $ HashMap.fromList resolvers
+  where
+    resolvers =
+        [ ("firstName", firstNameResolver)
+        , ("lastName", lastNameResolver)
+        ]
+    firstNameResolver = Out.Resolver firstNameField $ pure $ String "Friedrich"
+    lastNameResolver = Out.Resolver lastNameField $ pure $ String "Nietzsche"
+    firstNameField = Out.Field Nothing (Out.NonNullScalarType string) HashMap.empty
+    lastNameField = Out.Field Nothing (Out.NonNullScalarType string) HashMap.empty
 
 spec :: Spec
 spec =
-    describe "execute" $
+    describe "execute" $ do
         it "skips unknown fields" $
             let expected = Aeson.object
-                    ["data" .= Aeson.object ["count" .= (8 :: Int)]]
+                    [ "data" .= Aeson.object
+                        [ "philosopher" .= Aeson.object
+                            [ "firstName" .= ("Friedrich" :: String)
+                            ]
+                        ]
+                    ]
                 execute' = execute schema (mempty :: HashMap Name Aeson.Value)
                 actual = runIdentity
                     $ either parseError execute'
-                    $ parse document "" "{ count number }"
+                    $ parse document "" "{ philosopher { firstName surname } }"
+             in actual `shouldBe` expected
+        it "merges selections" $
+            let expected = Aeson.object
+                    [ "data" .= Aeson.object
+                        [ "philosopher" .= Aeson.object
+                            [ "firstName" .= ("Friedrich" :: String)
+                            , "lastName" .= ("Nietzsche" :: String)
+                            ]
+                        ]
+                    ]
+                execute' = execute schema (mempty :: HashMap Name Aeson.Value)
+                actual = runIdentity
+                    $ either parseError execute'
+                    $ parse document "" "{ philosopher { firstName } philosopher { lastName } }"
              in actual `shouldBe` expected