From 523d16bbaa107925ad40acdb057b8129736a4f04 Mon Sep 17 00:00:00 2001
From: Antoine Cormouls <contact.antoine.cormouls@gmail.com>
Date: Fri, 16 Aug 2019 00:43:09 +0200
Subject: [PATCH 1/3] Add Spec

---
 spec/ParseGraphQLServer.spec.js | 36 +++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/spec/ParseGraphQLServer.spec.js b/spec/ParseGraphQLServer.spec.js
index be2caa8550..fff113b581 100644
--- a/spec/ParseGraphQLServer.spec.js
+++ b/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`

From 3a69d8ac590e12ac4523a890561f828ca4103f0f Mon Sep 17 00:00:00 2001
From: Antoine Cormouls <contact.antoine.cormouls@gmail.com>
Date: Fri, 16 Aug 2019 00:51:59 +0200
Subject: [PATCH 2/3] Fix Undefined Array

---
 src/GraphQL/loaders/parseClassTypes.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/GraphQL/loaders/parseClassTypes.js b/src/GraphQL/loaders/parseClassTypes.js
index 0bbd184822..2fa85d48d6 100644
--- a/src/GraphQL/loaders/parseClassTypes.js
+++ b/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 &&

From 3160f7e81d2677375f154f2dd29955adfa8b8ca1 Mon Sep 17 00:00:00 2001
From: Antoine Cormouls <contact.antoine.cormouls@gmail.com>
Date: Fri, 16 Aug 2019 01:33:19 +0200
Subject: [PATCH 3/3] Nullability policy

---
 spec/ParseGraphQLServer.spec.js        | 8 ++------
 src/GraphQL/loaders/parseClassTypes.js | 2 +-
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/spec/ParseGraphQLServer.spec.js b/spec/ParseGraphQLServer.spec.js
index fff113b581..b77e8a1105 100644
--- a/spec/ParseGraphQLServer.spec.js
+++ b/spec/ParseGraphQLServer.spec.js
@@ -5723,7 +5723,7 @@ describe('ParseGraphQLServer', () => {
           expect(getResult.data.objects.someClasses.results.length).toEqual(2);
         });
 
-        it('should support undefined array values', async () => {
+        it('should support undefined array', async () => {
           const schema = await new Parse.Schema('SomeClass');
           schema.addArray('someArray');
           await schema.save();
@@ -5752,11 +5752,7 @@ describe('ParseGraphQLServer', () => {
               objectId: obj.id,
             },
           });
-
-          expect(
-            Array.isArray(getResult.data.objects.someClass.someArray)
-          ).toBeTruthy();
-          expect(getResult.data.objects.someClass.someArray.length).toEqual(0);
+          expect(getResult.data.objects.someClass.someArray).toEqual(null);
         });
 
         it('should support null values', async () => {
diff --git a/src/GraphQL/loaders/parseClassTypes.js b/src/GraphQL/loaders/parseClassTypes.js
index 2fa85d48d6..fb1de5bf30 100644
--- a/src/GraphQL/loaders/parseClassTypes.js
+++ b/src/GraphQL/loaders/parseClassTypes.js
@@ -639,7 +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 [];
+              if (!source[field]) return null;
               return source[field].map(async elem => {
                 if (
                   elem.className &&