Add revert() instance method to ParseObject

Author: andrewimm

src/ParseObject.js

@@ -847,6 +847,14 @@ export default class ParseObject {
     return this.set('ACL', acl, options);
   }
 
+  /**
+   * Clears any changes to this object made since the last call to save()
+   * @method revert
+   */
+  revert(): void {
+    this._clearPendingOps();
+  }
+
   /**
    * Clears all attributes on a model
    * @method clear

src/__tests__/ParseObject-test.js

@@ -767,6 +767,23 @@ describe('ParseObject', () => {
     expect(o.existed()).toBe(true);
   });
 
+  it('can revert unsaved ops', () => {
+    var o = ParseObject.fromJSON({
+      className: 'Item',
+      objectId: 'canrevert',
+      count: 5
+    });
+    o.set({ cool: true });
+    o.increment('count');
+    expect(o.get('cool')).toBe(true);
+    expect(o.get('count')).toBe(6);
+    o.revert();
+    expect(o.get('cool')).toBe(undefined);
+    expect(o.op('cool')).toBe(undefined);
+    expect(o.get('count')).toBe(5);
+    expect(o.op('count')).toBe(undefined);
+  });
+
   it('can save the object', asyncHelper((done) => {
     CoreManager.getRESTController()._setXHR(
       mockXHR([{