fix(rxjs): asap should runGuarded to let error inZone (#884)

* fix(rxjs): asap should runGuarded to let error inZone

* add document for how to load rxjs patch

Author: JiaLiPassion

NON-STANDARD-APIS.md

@@ -103,3 +103,61 @@ for example, if you want to add MediaQuery patch, you should do like this.
   <script src="path/zone.js"></script> 
   <script src="path/webapis-media-query.js"></script> 
 ```  
+
+* rxjs
+
+`zone.js` also provide a `rxjs` patch to make sure rxjs Observable/Subscription/Operator run in correct zone.
+for detail please refer to [pull request 843](https://github.com/angular/zone.js/pull/843), the following sample code describe the idea.
+
+```
+const constructorZone = Zone.current.fork({name: 'constructor'});
+const subscriptionZone = Zone.current.fork({name: 'subscription'});
+const operatorZone = Zone.current.fork({name: 'operator'});
+
+let observable;
+let subscriber;
+constructorZone.run(() => {
+  observable = new Observable((_subscriber) => {
+    subscriber = _subscriber;
+    console.log('current zone when construct observable:', Zone.current.name); // will output constructor.
+    return () => {
+      console.log('current zone when unsubscribe observable:', Zone.current.name); // will output constructor.
+    }
+  });
+});
+
+subscriptionZone.run(() => {
+  observable.subscribe(() => {
+    console.log('current zone when subscription next', Zone.current.name); // will output subscription. 
+  }, () => {
+    console.log('current zone when subscription error', Zone.current.name); // will output subscription. 
+  }, () => {
+    console.log('current zone when subscription complete', Zone.current.name); // will output subscription. 
+  });
+});
+
+operatorZone.run(() => {
+  observable.map(() => {
+    console.log('current zone when map operator', Zone.current.name); // will output operator. 
+  });
+});
+```
+
+currently basically all `rxjs` API include
+
+- Observable
+- Subscription
+- Subscriber
+- Operators 
+- Scheduler 
+
+are patched, so they will run in the correct zone.
+
+## Usage.
+
+for example, in angular application, you can load this patch in your `app.module.ts`.
+
+```
+import 'zone.js/dist/zone-patch-rxjs';
+```
+

lib/rxjs/rxjs.ts

@@ -340,7 +340,7 @@ import {rxSubscriber} from 'rxjs/symbol/rxSubscriber';
         const action = workArgs.length > 0 ? workArgs[0] : undefined;
         const scheduleZone = action && action[zoneSymbol];
         if (scheduleZone && scheduleZone !== Zone.current) {
-          return scheduleZone.run(work, this, arguments);
+          return scheduleZone.runGuarded(work, this, arguments);
         } else {
           return work.apply(this, arguments);
         }

test/rxjs/rxjs.asap.spec.ts

@@ -0,0 +1,51 @@
+/**
+ * @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 * as Rx from 'rxjs/Rx';
+import {asyncTest} from '../test-util';
+
+describe('Scheduler.asap', () => {
+  let log: string[];
+  let errorCallback: Function;
+  const constructorZone: Zone = Zone.root.fork({
+    name: 'Constructor Zone',
+    onHandleError: (delegate: ZoneDelegate, currentZone: Zone, targetZone: Zone, error: Error) => {
+      log.push('error' + error.message);
+      const result = delegate.handleError(targetZone, error);
+      errorCallback && errorCallback();
+      return false;
+    }
+  });
+
+  beforeEach(() => {
+    log = [];
+  });
+
+  it('scheduler asap error should run in correct zone', asyncTest((done: any) => {
+       let observable: any;
+       constructorZone.run(() => {
+         observable = Rx.Observable.of(1, 2, 3).observeOn(Rx.Scheduler.asap);
+       });
+
+       errorCallback = () => {
+         expect(log).toEqual(['erroroops']);
+         setTimeout(done, 0);
+       };
+
+       Zone.root.run(() => {
+         observable
+             .map((value: number) => {
+               if (value === 3) {
+                 throw new Error('oops');
+               }
+               return value;
+             })
+             .subscribe((value: number) => {});
+       });
+     }, Zone.root));
+});

test/rxjs/rxjs.spec.ts

@@ -7,6 +7,7 @@
  */
 import '../../lib/rxjs/rxjs';
 import './rxjs.common.spec';
+import './rxjs.asap.spec';
 import './rxjs.bindCallback.spec';
 import './rxjs.bindNodeCallback.spec';
 import './rxjs.combineLatest.spec';