GraphQL: Fix undefined Array

spec/ParseGraphQLServer.spec.js

@@ -5723,6 +5723,42 @@ describe('ParseGraphQLServer', () => {
  expect(getResult.data.objects.someClasses.results.length).toEqual(2);
  });
 
+ it('should support undefined array values', async () => {
+ const schema = await new Parse.Schema('SomeClass');
+ schema.addArray('someArray');
+ await schema.save();
+
+ const obj = new Parse.Object('SomeClass');
+ await obj.save();
+
+ await parseGraphQLServer.parseGraphQLSchema.databaseController.schemaCache.clear();
+
+ const getResult = await apolloClient.query({
+ query: gql`
+ query GetSomeObject($objectId: ID!) {
+ objects {
+ someClass(objectId: $objectId) {
+ objectId
+ someArray {
+ ... on Element {
+ value
+ }
+ }
+ }
+ }
+ }
+ `,
+ variables: {
+ objectId: obj.id,
+ },
+ });
+
+ expect(
+ Array.isArray(getResult.data.objects.someClass.someArray)
+ ).toBeTruthy();
+ expect(getResult.data.objects.someClass.someArray.length).toEqual(0);
+ });
+
  it('should support null values', async () => {
  const createResult = await apolloClient.mutate({
  mutation: gql`

src/GraphQL/loaders/parseClassTypes.js

@@ -639,6 +639,7 @@ const load = (
  description: `Use Inline Fragment on Array to get results: https://graphql.org/learn/queries/#inline-fragments`,
  type,
  async resolve(source) {
+ if (!source[field]) return [];
  return source[field].map(async elem => {
  if (
  elem.className &&