fix(browser): should not throw with frozen prototypes (#351)

Author: marclaval

lib/browser/define-property.ts

@@ -28,7 +28,7 @@ export function propertyPatch() {
   };
 
   Object.create = function (obj, proto) {
-    if (typeof proto === 'object') {
+    if (typeof proto === 'object' && !Object.isFrozen(proto)) {
       Object.keys(proto).forEach(function (prop) {
         proto[prop] = rewriteDescriptor(obj, prop, proto[prop]);
       });

test/browser/registerElement.spec.ts

@@ -89,7 +89,7 @@ describe('document.registerElement', ifEnvSupports(registerElement, function ()
       var proto = Object.create(HTMLElement.prototype);
 
       Object.defineProperty(proto, 'createdCallback', <any>{
-        writeable: false,
+        writable: false,
         configurable: false,
         value: checkZone
       });
@@ -112,7 +112,7 @@ describe('document.registerElement', ifEnvSupports(registerElement, function ()
 
       Object.defineProperties(proto, {
         createdCallback: <any>{
-          writeable: false,
+          writable: false,
           configurable: false,
           value: checkZone
         }
@@ -129,6 +129,26 @@ describe('document.registerElement', ifEnvSupports(registerElement, function ()
     var elt = document.createElement('x-props-desc');
   });
 
+  it('should not throw with frozen prototypes ', function () {
+    testZone.run(function() {
+
+      var proto = Object.create(HTMLElement.prototype, Object.freeze(<PropertyDescriptorMap>{createdCallback: <PropertyDescriptor>{
+        value: () => {},
+        writable: true,
+        configurable: true
+      }}));
+
+      Object.defineProperty(proto, 'createdCallback', <any>{
+        writable: false,
+        configurable: false
+      });
+
+      expect(function() {
+        (<any>document).registerElement('x-frozen-desc', { prototype: proto });
+      }).not.toThrow();
+    });
+  });
+
 
   it('should check bind callback if not own property', function (done) {
     testZone.run(function() {