How to debug uncaught (in promise): EmptyError: no elements in sequence caused by router.navigate?

Question

I'm trying to implement a simple angular route

const appRoutes: Routes = [
   { path: ''        ,redirectTo: '/recipes', pathMatch: 'full'},
   { path: 'recipes'              , component: RecipesComponent},
   { path: 'recipes/:recipeName'  , component: RecipesComponent},
];

in some component that generates the list, i have a function that on click of a updates state variable and routes, though I also have fetching mechanism subscriber happening on initialization.

  ngOnInit() {
    this.route.params
      .subscribe(
        (params: {Params}) => {

          this.selectedRecipe = this.findRecipeByName(params['recipeName']);  
        });
  }


   navRecipe(recipeName: string): void {
      let path = '/recipes/' + recipeName;
      this.selectedRecipe = this.findRecipeByName(recipeName);
      this.router.navigate([path]);
   }

But when I try to click on a link that reroutes to component with parameter I get the following:

core.js:1350 ERROR Error: Uncaught (in promise): EmptyError: no elements in sequence
EmptyError: no elements in sequence
    at new EmptyError (EmptyError.js:28)
    at FirstSubscriber._complete (first.js:154)
    at FirstSubscriber.Subscriber.complete (Subscriber.js:122)
    at MergeMapSubscriber._complete (mergeMap.js:150)
    at MergeMapSubscriber.Subscriber.complete (Subscriber.js:122)
    at MapSubscriber.Subscriber._complete (Subscriber.js:140)
    at MapSubscriber.Subscriber.complete (Subscriber.js:122)
    at EmptyObservable._subscribe (EmptyObservable.js:83)
    at EmptyObservable.Observable._trySubscribe (Observable.js:172)
    at EmptyObservable.Observable.subscribe (Observable.js:160)
    at new EmptyError (EmptyError.js:28)
    at FirstSubscriber._complete (first.js:154)
    at FirstSubscriber.Subscriber.complete (Subscriber.js:122)
    at MergeMapSubscriber._complete (mergeMap.js:150)
    at MergeMapSubscriber.Subscriber.complete (Subscriber.js:122)
    at MapSubscriber.Subscriber._complete (Subscriber.js:140)
    at MapSubscriber.Subscriber.complete (Subscriber.js:122)
    at EmptyObservable._subscribe (EmptyObservable.js:83)
    at EmptyObservable.Observable._trySubscribe (Observable.js:172)
    at EmptyObservable.Observable.subscribe (Observable.js:160)
    at resolvePromise (zone.js:824)
    at resolvePromise (zone.js:795)
    at eval (zone.js:873)
    at ZoneDelegate.invokeTask (zone.js:425)
    at Object.onInvokeTask (core.js:4621)
    at ZoneDelegate.invokeTask (zone.js:424)
    at Zone.runTask (zone.js:192)
    at drainMicroTaskQueue (zone.js:602)
    at ZoneTask.invokeTask [as invoke] (zone.js:503)
    at invokeTask (zone.js:1540)

Answer 1

I encountered the same error with Angular v 4.4.6. There were two alternative solutions I found to resolve the error. One was adding pathMatch: 'full' to every route definition. The other was downgrading rxjs below v5.5.3. If one does not work for you perhaps the other will.

update: it appears the problem has been fixed in rxjs v5.5.5. In a project using Angular 5.0.5, after upgrading rxjs to v5.5.5 the error stopped happening.

Answer 2

Angular latest version bug. Add pathMatch: 'full' to all routes.

 {
    path: '',
    component: HomeComponent,
    pathMatch: 'full'
  },
  {
   path: 'about',
   component: AboutComponent,
   pathMatch: 'full'
  },