fix(router): navigating to the current location works (angular#19463)

Closes angular#13340

PR Close angular#19463

Author: vsavkin

packages/common/testing/src/location_mock.ts

@@ -41,7 +41,9 @@ export class SpyLocation implements Location {
     return currPath == givenPath + (query.length > 0 ? ('?' + query) : '');
   }
 
-  simulateUrlPop(pathname: string) { this._subject.emit({'url': pathname, 'pop': true}); }
+  simulateUrlPop(pathname: string) {
+    this._subject.emit({'url': pathname, 'pop': true, 'type': 'popstate'});
+  }
 
   simulateHashChange(pathname: string) {
     // Because we don't prevent the native event, the browser will independently update the path

packages/router/src/router.ts

@@ -43,12 +43,12 @@ declare let Zone: any;
  */
 export interface NavigationExtras {
   /**
-  * Enables relative navigation from the current ActivatedRoute.
-  *
-  * Configuration:
-  *
-  * ```
-  * [{
+   * Enables relative navigation from the current ActivatedRoute.
+   *
+   * Configuration:
+   *
+   * ```
+   * [{
   *   path: 'parent',
   *   component: ParentComponent,
   *   children: [{
@@ -59,92 +59,92 @@ export interface NavigationExtras {
   *     component: ChildComponent
   *   }]
   * }]
-  * ```
-  *
-  * Navigate to list route from child route:
-  *
-  * ```
-  *  @Component({...})
-  *  class ChildComponent {
+   * ```
+   *
+   * Navigate to list route from child route:
+   *
+   * ```
+   *  @Component({...})
+   *  class ChildComponent {
   *    constructor(private router: Router, private route: ActivatedRoute) {}
   *
   *    go() {
   *      this.router.navigate(['../list'], { relativeTo: this.route });
   *    }
   *  }
-  * ```
-  */
+   * ```
+   */
   relativeTo?: ActivatedRoute|null;
 
   /**
-  * Sets query parameters to the URL.
-  *
-  * ```
-  * // Navigate to /results?page=1
-  * this.router.navigate(['/results'], { queryParams: { page: 1 } });
-  * ```
-  */
+   * Sets query parameters to the URL.
+   *
+   * ```
+   * // Navigate to /results?page=1
+   * this.router.navigate(['/results'], { queryParams: { page: 1 } });
+   * ```
+   */
   queryParams?: Params|null;
 
   /**
-  * Sets the hash fragment for the URL.
-  *
-  * ```
-  * // Navigate to /results#top
-  * this.router.navigate(['/results'], { fragment: 'top' });
-  * ```
-  */
+   * Sets the hash fragment for the URL.
+   *
+   * ```
+   * // Navigate to /results#top
+   * this.router.navigate(['/results'], { fragment: 'top' });
+   * ```
+   */
   fragment?: string;
 
   /**
-  * Preserves the query parameters for the next navigation.
-  *
-  * deprecated, use `queryParamsHandling` instead
-  *
-  * ```
-  * // Preserve query params from /results?page=1 to /view?page=1
-  * this.router.navigate(['/view'], { preserveQueryParams: true });
-  * ```
-  *
-  * @deprecated since v4
-  */
+   * Preserves the query parameters for the next navigation.
+   *
+   * deprecated, use `queryParamsHandling` instead
+   *
+   * ```
+   * // Preserve query params from /results?page=1 to /view?page=1
+   * this.router.navigate(['/view'], { preserveQueryParams: true });
+   * ```
+   *
+   * @deprecated since v4
+   */
   preserveQueryParams?: boolean;
 
   /**
-  *  config strategy to handle the query parameters for the next navigation.
-  *
-  * ```
-  * // from /results?page=1 to /view?page=1&page=2
-  * this.router.navigate(['/view'], { queryParams: { page: 2 },  queryParamsHandling: "merge" });
-  * ```
-  */
+   *  config strategy to handle the query parameters for the next navigation.
+   *
+   * ```
+   * // from /results?page=1 to /view?page=1&page=2
+   * this.router.navigate(['/view'], { queryParams: { page: 2 },  queryParamsHandling: "merge" });
+   * ```
+   */
   queryParamsHandling?: QueryParamsHandling|null;
   /**
-  * Preserves the fragment for the next navigation
-  *
-  * ```
-  * // Preserve fragment from /results#top to /view#top
-  * this.router.navigate(['/view'], { preserveFragment: true });
-  * ```
-  */
+   * Preserves the fragment for the next navigation
+   *
+   * ```
+   * // Preserve fragment from /results#top to /view#top
+   * this.router.navigate(['/view'], { preserveFragment: true });
+   * ```
+   */
   preserveFragment?: boolean;
   /**
-  * Navigates without pushing a new state into history.
-  *
-  * ```
-  * // Navigate silently to /view
-  * this.router.navigate(['/view'], { skipLocationChange: true });
-  * ```
-  */
+   * Navigates without pushing a new state into history.
+   *
+   * ```
+   * // Navigate silently to /view
+   * this.router.navigate(['/view'], { skipLocationChange: true });
+   * ```
+   */
   skipLocationChange?: boolean;
   /**
-  * Navigates while replacing the current state in history.
-  *
-  * ```
-  * // Navigate to /view
-  * this.router.navigate(['/view'], { replaceUrl: true });
-  * ```
-  */
+   * Navigates while replacing the current state in history.
+   *
+   * ```
+   * // Navigate to /view
+   * this.router.navigate(['/view'], { replaceUrl: true });
+   * ```
+   */
   replaceUrl?: boolean;
 }
 
@@ -518,11 +518,18 @@ export class Router {
 
     // Because of a bug in IE and Edge, the location class fires two events (popstate and
     // hashchange) every single time. The second one should be ignored. Otherwise, the URL will
-    // flicker.
+    // flicker. Handles the case when a popstate was emitted first.
     if (lastNavigation && source == 'hashchange' && lastNavigation.source === 'popstate' &&
         lastNavigation.rawUrl.toString() === rawUrl.toString()) {
       return Promise.resolve(true);  // return value is not used
     }
+    // Because of a bug in IE and Edge, the location class fires two events (popstate and
+    // hashchange) every single time. The second one should be ignored. Otherwise, the URL will
+    // flicker. Handles the case when a hashchange was emitted first.
+    if (lastNavigation && source == 'popstate' && lastNavigation.source === 'hashchange' &&
+        lastNavigation.rawUrl.toString() === rawUrl.toString()) {
+      return Promise.resolve(true);  // return value is not used
+    }
 
     let resolve: any = null;
     let reject: any = null;
@@ -545,7 +552,7 @@ export class Router {
     const url = this.urlHandlingStrategy.extract(rawUrl);
     const urlTransition = !this.navigated || url.toString() !== this.currentUrlTree.toString();
 
-    if (urlTransition && this.urlHandlingStrategy.shouldProcessUrl(rawUrl)) {
+    if (this.urlHandlingStrategy.shouldProcessUrl(rawUrl)) {
       (this.events as Subject<Event>).next(new NavigationStart(id, this.serializeUrl(url)));
       Promise.resolve()
           .then(

packages/router/test/integration.spec.ts

@@ -50,6 +50,29 @@ describe('Integration', () => {
        expect(fixture.nativeElement).toHaveText('route');
      })));
 
+  it('should navigate to the current URL',
+     fakeAsync(inject([Router, Location], (router: Router) => {
+       router.resetConfig([
+         {path: '', component: SimpleCmp},
+         {path: 'simple', component: SimpleCmp},
+       ]);
+
+       const fixture = createRoot(router, RootCmp);
+       const events: Event[] = [];
+       router.events.subscribe(e => onlyNavigationStartAndEnd(e) && events.push(e));
+
+       router.navigateByUrl('/simple');
+       tick();
+
+       router.navigateByUrl('/simple');
+       tick();
+
+       expectEvents(events, [
+         [NavigationStart, '/simple'], [NavigationEnd, '/simple'], [NavigationStart, '/simple'],
+         [NavigationEnd, '/simple']
+       ]);
+     })));
+
   describe('should execute navigations serially', () => {
     let log: any[] = [];
 
@@ -428,7 +451,7 @@ describe('Integration', () => {
        }]);
 
        const recordedEvents: any[] = [];
-       router.events.forEach(e => e instanceof RouterEvent && recordedEvents.push(e));
+       router.events.forEach(e => onlyNavigationStartAndEnd(e) && recordedEvents.push(e));
 
        router.navigateByUrl('/team/22/user/victor');
        advance(fixture);
@@ -442,15 +465,8 @@ describe('Integration', () => {
        expect(fixture.nativeElement).toHaveText('team 22 [ user fedor, right:  ]');
 
        expectEvents(recordedEvents, [
-         [NavigationStart, '/team/22/user/victor'], [RoutesRecognized, '/team/22/user/victor'],
-         [GuardsCheckStart, '/team/22/user/victor'], [GuardsCheckEnd, '/team/22/user/victor'],
-         [ResolveStart, '/team/22/user/victor'], [ResolveEnd, '/team/22/user/victor'],
-         [NavigationEnd, '/team/22/user/victor'],
-
-         [NavigationStart, '/team/22/user/fedor'], [RoutesRecognized, '/team/22/user/fedor'],
-         [GuardsCheckStart, '/team/22/user/fedor'], [GuardsCheckEnd, '/team/22/user/fedor'],
-         [ResolveStart, '/team/22/user/fedor'], [ResolveEnd, '/team/22/user/fedor'],
-         [NavigationEnd, '/team/22/user/fedor']
+         [NavigationStart, '/team/22/user/victor'], [NavigationEnd, '/team/22/user/victor'],
+         [NavigationStart, '/team/22/user/fedor'], [NavigationEnd, '/team/22/user/fedor']
        ]);
      })));
 
@@ -3489,34 +3505,30 @@ describe('Integration', () => {
            }]);
 
            const events: any[] = [];
-           router.events.subscribe(e => e instanceof RouterEvent && events.push(e));
+           router.events.subscribe(e => onlyNavigationStartAndEnd(e) && events.push(e));
 
            location.go('/include/user/kate(aux:excluded)');
            advance(fixture);
 
            expect(location.path()).toEqual('/include/user/kate(aux:excluded)');
-           expectEvents(events, [
-             [NavigationStart, '/include/user/kate'], [RoutesRecognized, '/include/user/kate'],
-             [GuardsCheckStart, '/include/user/kate'], [GuardsCheckEnd, '/include/user/kate'],
-             [ResolveStart, '/include/user/kate'], [ResolveEnd, '/include/user/kate'],
-             [NavigationEnd, '/include/user/kate']
-           ]);
+           expectEvents(
+               events,
+               [[NavigationStart, '/include/user/kate'], [NavigationEnd, '/include/user/kate']]);
            events.splice(0);
 
            location.go('/include/user/kate(aux:excluded2)');
            advance(fixture);
-           expectEvents(events, []);
+           expectEvents(
+               events,
+               [[NavigationStart, '/include/user/kate'], [NavigationEnd, '/include/user/kate']]);
+           events.splice(0);
 
            router.navigateByUrl('/include/simple');
            advance(fixture);
 
            expect(location.path()).toEqual('/include/simple(aux:excluded2)');
-           expectEvents(events, [
-             [NavigationStart, '/include/simple'], [RoutesRecognized, '/include/simple'],
-             [GuardsCheckStart, '/include/simple'], [GuardsCheckEnd, '/include/simple'],
-             [ResolveStart, '/include/simple'], [ResolveEnd, '/include/simple'],
-             [NavigationEnd, '/include/simple']
-           ]);
+           expectEvents(
+               events, [[NavigationStart, '/include/simple'], [NavigationEnd, '/include/simple']]);
          })));
     });
   });
@@ -3635,6 +3647,10 @@ function expectEvents(events: Event[], pairs: any[]) {
   }
 }
 
+function onlyNavigationStartAndEnd(e: Event): boolean {
+  return e instanceof NavigationStart || e instanceof NavigationEnd;
+}
+
 @Component(
     {selector: 'link-cmp', template: `<a routerLink="/team/33/simple" [target]="'_self'">link</a>`})
 class StringLinkCmp {