Fix dirtyKeys() and dirty(key:) on beforeSave when updating objects.

spec/ParseAPI.spec.js

@@ -429,6 +429,47 @@ describe('miscellaneous', function() {
     });
   });
 
+  it('test beforeSave get dirtyKeys on update', function(done) {
+    var triggerTime = 0;
+    // Register a mock beforeSave hook
+    Parse.Cloud.beforeSave('GameScore', function(req, res) {
+      var object = req.object;
+      expect(object instanceof Parse.Object).toBeTruthy();
+      expect(object.get('fooAgain')).toEqual('barAgain');
+      if (triggerTime == 0) {
+        // Create
+        expect(object.get('foo')).toEqual('bar');
+      } else if (triggerTime == 1) {
+        // Update
+        expect(object.dirtyKeys()).toEqual(['foo']);
+        expect(object.dirty('foo')).toBeTruthy();
+        expect(object.get('foo')).toEqual('baz');
+      } else {
+        res.error();
+      }
+      triggerTime++;
+      res.success();
+    });
+
+    var obj = new Parse.Object('GameScore');
+    obj.set('foo', 'bar');
+    obj.set('fooAgain', 'barAgain');
+    obj.save().then(function() {
+      // We only update foo
+      obj.set('foo', 'baz');
+      return obj.save();
+    }).then(function() {
+      // Make sure the checking has been triggered
+      expect(triggerTime).toBe(2);
+      // Clear mock beforeSave
+      delete Parse.Cloud.Triggers.beforeSave.GameScore;
+      done();
+    }, function(error) {
+      fail(error);
+      done();
+    });
+  });
+
   it('test afterSave get full object on create and update', function(done) {
     var triggerTime = 0;
     // Register a mock beforeSave hook

src/RestWrite.js

@@ -116,18 +116,23 @@ RestWrite.prototype.runBeforeTrigger = function() {
   if (this.query && this.query.objectId) {
     extraData.objectId = this.query.objectId;
   }
-  // Build the inflated object, for a create write, originalData is empty
-  var inflatedObject = triggers.inflate(extraData, this.originalData);;
-  inflatedObject._finishFetch(this.data);
-  // Build the original object, we only do this for a update write
-  var originalObject;
+
+  let originalObject = null;
+  let updatedObject = null;
   if (this.query && this.query.objectId) {
+    // This is an update for existing object.
     originalObject = triggers.inflate(extraData, this.originalData);
+    updatedObject = triggers.inflate(extraData, this.originalData);
+    updatedObject.set(Parse._decode(undefined, this.data));
+  } else {
+    // This is create of an object, so no original object exists.
+    // TODO: (nlutsenko) Use the same flow as for creation, when _Session triggers support is removed.
+    updatedObject = triggers.inflate(extraData, this.data);
   }
 
   return Promise.resolve().then(() => {
     return triggers.maybeRunTrigger(
-      'beforeSave', this.auth, inflatedObject, originalObject);
+      'beforeSave', this.auth, updatedObject, originalObject);
   }).then((response) => {
     if (response && response.object) {
       this.data = response.object;