fix(toString): fix #666, Zone patched method toString should like before patched (#686)

Author: JiaLiPassion

Diff for: lib/browser/browser.ts

@@ -7,6 +7,7 @@
  */
 
 import {patchTimer} from '../common/timers';
+import {patchFuncToString} from '../common/to-string';
 import {findEventTask, patchClass, patchEventTargetMethods, patchMethod, patchPrototype, zoneSymbol} from '../common/utils';
 
 import {propertyPatch} from './define-property';
@@ -151,6 +152,9 @@ if (_global['navigator'] && _global['navigator'].geolocation) {
   patchPrototype(_global['navigator'].geolocation, ['getCurrentPosition', 'watchPosition']);
 }
 
+// patch Func.prototype.toString to let them look like native
+patchFuncToString();
+
 // handle unhandled promise rejection
 function findPromiseRejectionHandler(evtName: string) {
   return function(e: any) {

Diff for: lib/browser/register-element.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {isBrowser, isMix} from '../common/utils';
+import {attachOriginToPatched, isBrowser, isMix} from '../common/utils';
 
 import {_redefineProperty} from './define-property';
 
@@ -39,4 +39,6 @@ export function registerElementPatch(_global: any) {
 
     return _registerElement.apply(document, [name, opts]);
   };
+
+  attachOriginToPatched((<any>document).registerElement, _registerElement);
 }

Diff for: lib/common/to-string.ts

@@ -0,0 +1,36 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import {zoneSymbol} from './utils';
+
+// override Function.prototype.toString to make zone.js patched function
+// look like native function
+export function patchFuncToString() {
+  const originalFunctionToString = Function.prototype.toString;
+  const g: any =
+      typeof window !== 'undefined' && window || typeof self !== 'undefined' && self || global;
+  Function.prototype.toString = function() {
+    if (typeof this === 'function') {
+      if (this[zoneSymbol('OriginalDelegate')]) {
+        return originalFunctionToString.apply(this[zoneSymbol('OriginalDelegate')], arguments);
+      }
+      if (this === Promise) {
+        const nativePromise = g[zoneSymbol('Promise')];
+        if (nativePromise) {
+          return originalFunctionToString.apply(nativePromise, arguments);
+        }
+      }
+      if (this === Error) {
+        const nativeError = g[zoneSymbol('Error')];
+        if (nativeError) {
+          return originalFunctionToString.apply(nativeError, arguments);
+        }
+      }
+    }
+    return originalFunctionToString.apply(this, arguments);
+  };
+}

Diff for: lib/common/utils.ts

@@ -34,9 +34,11 @@ export function patchPrototype(prototype: any, fnNames: string[]) {
     const delegate = prototype[name];
     if (delegate) {
       prototype[name] = ((delegate: Function) => {
-        return function() {
+        const patched: any = function() {
           return delegate.apply(this, bindArguments(<any>arguments, source + '.' + name));
         };
+        attachOriginToPatched(patched, delegate);
+        return patched;
       })(delegate);
     }
   }
@@ -401,6 +403,8 @@ const originalInstanceKey = zoneSymbol('originalInstance');
 export function patchClass(className: string) {
   const OriginalClass = _global[className];
   if (!OriginalClass) return;
+  // keep original class in global
+  _global[zoneSymbol(className)] = OriginalClass;
 
   _global[className] = function() {
     const a = bindArguments(<any>arguments, className);
@@ -425,6 +429,9 @@ export function patchClass(className: string) {
     }
   };
 
+  // attach original delegate to patched function
+  attachOriginToPatched(_global[className], OriginalClass);
+
   const instance = new OriginalClass(function() {});
 
   let prop;
@@ -441,6 +448,10 @@ export function patchClass(className: string) {
           set: function(fn) {
             if (typeof fn === 'function') {
               this[originalInstanceKey][prop] = Zone.current.wrap(fn, className + '.' + prop);
+              // keep callback in wrapped function so we can
+              // use it in Function.prototype.toString to return
+              // the native one.
+              attachOriginToPatched(this[originalInstanceKey][prop], fn);
             } else {
               this[originalInstanceKey][prop] = fn;
             }
@@ -488,6 +499,7 @@ export function patchMethod(
   if (proto && !(delegate = proto[delegateName])) {
     delegate = proto[delegateName] = proto[name];
     proto[name] = createNamedFn(name, patchFn(delegate, delegateName, name));
+    attachOriginToPatched(proto[name], delegate);
   }
   return delegate;
 }
@@ -575,5 +587,9 @@ export function findEventTask(target: any, evtName: string): Task[] {
   return result;
 }
 
+export function attachOriginToPatched(patched: Function, original: any) {
+  (patched as any)[zoneSymbol('OriginalDelegate')] = original;
+}
+
 (Zone as any)[zoneSymbol('patchEventTargetMethods')] = patchEventTargetMethods;
 (Zone as any)[zoneSymbol('patchOnProperties')] = patchOnProperties;

Diff for: lib/node/node.ts

@@ -11,6 +11,7 @@ import './events';
 import './fs';
 
 import {patchTimer} from '../common/timers';
+import {patchFuncToString} from '../common/to-string';
 import {findEventTask, patchMacroTask, patchMicroTask, zoneSymbol} from '../common/utils';
 
 const set = 'set';
@@ -35,6 +36,9 @@ if (shouldPatchGlobalTimers) {
 patchProcess();
 handleUnhandledPromiseRejection();
 
+// patch Function.prototyp.toString
+patchFuncToString();
+
 // Crypto
 let crypto: any;
 try {

Diff for: test/common/toString.spec.ts

@@ -0,0 +1,32 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {zoneSymbol} from '../../lib/common/utils';
+import {ifEnvSupports} from '../test-util';
+
+const g: any =
+    typeof window !== 'undefined' && window || typeof self !== 'undefined' && self || global;
+describe('global function patch', () => {
+  describe('isOriginal', () => {
+    it('setTimeout toString should be the same with non patched setTimeout', () => {
+      expect(Function.prototype.toString.call(setTimeout))
+          .toEqual(Function.prototype.toString.call(g[zoneSymbol('setTimeout')]));
+    });
+  });
+
+  describe('isNative', () => {
+    it('ZoneAwareError toString should look like native', () => {
+      expect(Function.prototype.toString.call(Error)).toContain('[native code]');
+    });
+
+    it('EventTarget addEventListener should look like native', ifEnvSupports('HTMLElement', () => {
+         expect(Function.prototype.toString.call(HTMLElement.prototype.addEventListener))
+             .toContain('[native code]');
+       }));
+  });
+});

Diff for: test/common_tests.ts

@@ -14,6 +14,7 @@ import './common/Promise.spec';
 import './common/Error.spec';
 import './common/setInterval.spec';
 import './common/setTimeout.spec';
+import './common/toString.spec';
 import './zone-spec/long-stack-trace-zone.spec';
 import './zone-spec/async-test.spec';
 import './zone-spec/sync-test.spec';