GraphQL: Allow true GraphQL Schema Customization (#6360)

* Allow real GraphQL Schema via ParseServer.start

* wip

* working

* tests ok

* add tests about enum/input use case

* Add async function based merge

* Better naming

* remove useless condition

src/GraphQL/helpers/objectsQueries.js

@@ -3,6 +3,11 @@ import { offsetToCursor, cursorToOffset } from 'graphql-relay';
 import rest from '../../rest';
 import { transformQueryInputToParse } from '../transformers/query';
 
+const needToGetAllKeys = (fields, keys) =>
+  keys
+    ? !!keys.split(',').find(keyName => !fields[keyName.split('.')[0]])
+    : true;
+
 const getObject = async (
   className,
   objectId,
@@ -12,10 +17,11 @@ const getObject = async (
   includeReadPreference,
   config,
   auth,
-  info
+  info,
+  parseClass
 ) => {
   const options = {};
-  if (keys) {
+  if (!needToGetAllKeys(parseClass.fields, keys)) {
     options.keys = keys;
   }
   if (include) {
@@ -133,7 +139,14 @@ const findObjects = async (
         // Silently replace the limit on the query with the max configured
         options.limit = config.maxLimit;
       }
-      if (keys) {
+      if (
+        !needToGetAllKeys(
+          parseClasses.find(
+            ({ className: parseClassName }) => className === parseClassName
+          ).fields,
+          keys
+        )
+      ) {
         options.keys = keys;
       }
       if (includeAll === true) {
@@ -313,4 +326,4 @@ const calculateSkipAndLimit = (
   };
 };
 
-export { getObject, findObjects, calculateSkipAndLimit };
+export { getObject, findObjects, calculateSkipAndLimit, needToGetAllKeys };