fix(router): handle URL that does not match a route

Closes #7349
Closes #7203

modules/angular2/src/router/router.ts

@@ -260,6 +260,7 @@ export class Router {
   }
 
   private _emitNavigationFinish(url): void { ObservableWrapper.callEmit(this._subject, url); }
+  _emitNavigationFail(url): void { ObservableWrapper.callError(this._subject, url); }
 
   private _afterPromiseFinishNavigating(promise: Promise<any>): Promise<any> {
     return PromiseWrapper.catchError(promise.then((_) => this._finishNavigating()), (err) => {
@@ -367,8 +368,8 @@ export class Router {
   /**
    * Subscribe to URL updates from the router
    */
-  subscribe(onNext: (value: any) => void): Object {
-    return ObservableWrapper.subscribe(this._subject, onNext);
+  subscribe(onNext: (value: any) => void, onError?: (value: any) => void): Object {
+    return ObservableWrapper.subscribe(this._subject, onNext, onError);
   }
 
 
@@ -451,6 +452,7 @@ export class RootRouter extends Router {
       // we call recognize ourselves
       this.recognize(change['url'])
           .then((instruction) => {
+            if (isPresent(instruction)) {
               this.navigateByInstruction(instruction, isPresent(change['pop']))
                   .then((_) => {
                     // this is a popstate event; no need to change the URL
@@ -476,6 +478,9 @@ export class RootRouter extends Router {
                       this._location.go(emitPath, emitQuery);
                     }
                   });
+            } else {
+              this._emitNavigationFail(change['url']);
+            }
           });
     });
 

modules/angular2/test/router/router_spec.ts

@@ -145,6 +145,22 @@ export function main() {
              });
        }));
 
+
+    it('should trigger the onError callback of a router change subscription if the URL does not match a route',
+       inject([AsyncTestCompleter], (async) => {
+         var outlet = makeDummyOutlet();
+
+         router.registerPrimaryOutlet(outlet)
+             .then((_) => router.config([new Route({path: '/a', component: DummyComponent})]))
+             .then((_) => {
+               router.subscribe((_) => {}, (url) => {
+                 expect(url).toEqual('b');
+                 async.done();
+               });
+               (<SpyLocation>location).simulateHashChange('b');
+             });
+       }));
+
     it('should navigate after being configured', inject([AsyncTestCompleter], (async) => {
          var outlet = makeDummyOutlet();