Ensure initialize() still works in single instance mode

Author: andrewimm

src/ParseObject.js

@@ -1473,13 +1473,13 @@ export default class ParseObject {
       parentProto = classMap[adjustedClassName].prototype;
     }
     var ParseObjectSubclass = function(attributes, options) {
+      this.className = adjustedClassName;
+      this._objCount = objectCount++;
       // Enable legacy initializers
       if (typeof this.initialize === 'function') {
         this.initialize.apply(this, arguments);
       }
 
-      this.className = adjustedClassName;
-      this._objCount = objectCount++;
       if (attributes && typeof attributes === 'object'){
         if (!this.set(attributes || {}, options)) {
           throw new Error('Can\'t create an invalid Parse Object');

src/__tests__/ParseObject-test.js

@@ -2090,4 +2090,15 @@ describe('ParseObject extensions', () => {
     f = new FeatureObject();
     expect(f.foo() + f.bar()).toBe('FB');
   });
+
+  it('can specify a custom initializer', () => {
+    var InitObject = ParseObject.extend('InitObject', {
+      initialize: function(attrs, options) {
+        this.set('field', 12);
+      }
+    });
+
+    var i = new InitObject()
+    expect(i.get('field')).toBe(12);
+  });
 });