Allow cloning of objects with readonly attributes

Author: andrewimm

src/ParseObject.js

@@ -780,12 +780,25 @@ export default class ParseObject {
    * @return {Parse.Object}
    */
   clone(): any {
-    var clone = new this.constructor();
+    let clone = new this.constructor();
     if (!clone.className) {
       clone.className = this.className;
     }
+    let attributes = this.attributes;
+    if (typeof this.constructor.readOnlyAttributes === 'function') {
+      let readonly = this.constructor.readOnlyAttributes() || [];
+      // Attributes are frozen, so we have to rebuild an object,
+      // rather than delete readonly keys
+      let copy = {};
+      for (let a in attributes) {
+        if (readonly.indexOf(a) < 0) {
+          copy[a] = attributes[a];
+        }
+      }
+      attributes = copy;
+    }
     if (clone.set) {
-      clone.set(this.attributes);
+      clone.set(attributes);
     }
     return clone;
   }

src/__tests__/ParseSession-test.js

@@ -127,4 +127,17 @@ describe('ParseSession', () => {
       done();
     });
   }));
+
+  it('can be cloned', () => {
+    var s = ParseObject.fromJSON({
+      className: '_Session',
+      sessionToken: '123abc',
+      foo: 12
+    });
+
+    var clone = s.clone();
+    expect(clone.className).toBe('_Session');
+    expect(clone.get('foo')).toBe(12);
+    expect(clone.get('sessionToken')).toBe(undefined);
+  });
 });

src/__tests__/ParseUser-test.js

@@ -85,6 +85,21 @@ describe('ParseUser', () => {
     expect(u2.getEmail()).toBe('bono@u2.com');
   });
 
+  it('can clone User objects', () => {
+    var u = ParseObject.fromJSON({
+      className: '_User',
+      username: 'user12',
+      email: 'user12@parse.com',
+      sessionToken: '123abc'
+    });
+
+    var clone = u.clone();
+    expect(clone.className).toBe('_User');
+    expect(clone.get('username')).toBe('user12');
+    expect(clone.get('email')).toBe('user12@parse.com');
+    expect(clone.get('sessionToken')).toBe(undefined);
+  });
+
   it('makes session tokens readonly', () => {
     var u = new ParseUser();
     expect(u.set.bind(u, 'sessionToken', 'token')).toThrow(