prevent conversion of array to object

Author: dplewis

spec/ParseObject.spec.js

@@ -572,15 +572,35 @@ describe('Parse.Object testing', () => {
     const obj = new TestObject();
     obj.set('items', [ { value: 'a', count: 5 }, { value: 'b', count: 1 } ]);
     await obj.save();
-
     obj.increment('items.0.count', 15);
     obj.increment('items.1.count', 4);
     await obj.save();
-
+    expect(obj.toJSON().items[0].value).toBe('a');
+    expect(obj.toJSON().items[1].value).toBe('b');
+    expect(obj.toJSON().items[0].count).toBe(20);
+    expect(obj.toJSON().items[1].count).toBe(5);
     const query = new Parse.Query(TestObject);
     const result = await query.get(obj.id);
+    expect(result.get('items')[0].value).toBe('a');
+    expect(result.get('items')[1].value).toBe('b');
     expect(result.get('items')[0].count).toBe(20);
     expect(result.get('items')[1].count).toBe(5);
+    expect(result.get('items')).toEqual(obj.get('items'));
+  });
+
+  it_only_db('mongo')('can increment array nested fields missing index', async () => {
+    const obj = new TestObject();
+    obj.set('items', []);
+    await obj.save();
+    obj.increment('items.1.count', 15);
+    await obj.save();
+    expect(obj.toJSON().items[0]).toBe(null);
+    expect(obj.toJSON().items[1].count).toBe(15);
+    const query = new Parse.Query(TestObject);
+    const result = await query.get(obj.id);
+    expect(result.get('items')[0]).toBe(null);
+    expect(result.get('items')[1].count).toBe(15);
+    expect(result.get('items')).toEqual(obj.get('items'));
   });
 
   it('addUnique with object', function (done) {

src/Controllers/DatabaseController.js

@@ -1851,6 +1851,13 @@ class DatabaseController {
         // only valid ops that produce an actionable result
         // the op may have happened on a keypath
         this._expandResultOnKeyPath(response, key, result);
+        // Revert array to object conversion on dot notation for arrays (e.g. "field.0.key")
+        if (key.includes('.')) {
+          const [field, index] = key.split('.');
+          if (!isNaN(index) && Array.isArray(result[field]) && !Array.isArray(response[field])) {
+            response[field] = result[field];
+          }
+        }
       }
     });
     return Promise.resolve(response);