fix(router): should navigate to the same url when config changes

Closes #15535

packages/router/src/router.ts

@@ -313,7 +313,7 @@ export class Router {
   get events(): Observable<Event> { return this.routerEvents; }
 
   /** @internal */
-  triggerEvent(e: Event) { this.routerEvents.next(e); }
+  triggerEvent(e: Event): void { this.routerEvents.next(e); }
 
   /**
    * Resets the configuration used for navigation and generating links.
@@ -332,10 +332,11 @@ export class Router {
   resetConfig(config: Routes): void {
     validateConfig(config);
     this.config = config;
+    this.navigated = false;
   }
 
   /** @docsNotRequired */
-  ngOnDestroy() { this.dispose(); }
+  ngOnDestroy(): void { this.dispose(); }
 
   /** Disposes of the router */
   dispose(): void {

packages/router/test/integration.spec.ts

@@ -398,6 +398,25 @@ describe('Integration', () => {
        expect(location.path()).toEqual('/team/22/user/victor');
      })));
 
+  it('should navigate to the same url when config changes',
+     fakeAsync(inject([Router, Location], (router: Router, location: Location) => {
+       const fixture = createRoot(router, RootCmp);
+
+       router.resetConfig([{path: 'a', component: SimpleCmp}]);
+
+       router.navigate(['/a']);
+       advance(fixture);
+       expect(location.path()).toEqual('/a');
+       expect(fixture.nativeElement).toHaveText('simple');
+
+       router.resetConfig([{path: 'a', component: RouteCmp}]);
+
+       router.navigate(['/a']);
+       advance(fixture);
+       expect(location.path()).toEqual('/a');
+       expect(fixture.nativeElement).toHaveText('route');
+     })));
+
   it('should navigate when locations changes',
      fakeAsync(inject([Router, Location], (router: Router, location: Location) => {
        const fixture = createRoot(router, RootCmp);