Handling Errors in NgRx Effects - Snippet 4 (TodoEffects)

todo-effects.ts

@Injectable()
export class TodoEffects {
  @Effect()
  public fetchListOfTodos$: Observable<void> = this.action$.pipe(
    ofType(ActionTypes.FETCH_TODO_LIST),
    switchMap(() =>
      this.todoListService.fetchTodoList().pipe(
        map((todos: Todo[]) => {
          return {
            type: ActionTypes.TODO_LIST_FETCHED,
            payload: { todos }
          };
        }),
        // handle failure in todoListService.fetchTodoList()
        catchError((error) => {
          return Observable.of({
            type: ActionTypes.FETCH_TODO_LIST_FAILED,
            payload: { error }
          });
        })
      )
    )
  );
}