map-operators-get-all-04.ts

export class BookEffects {
  @Effect() getOneBook$ = this.action$.pipe(
    ofType(INPUT_ACTION_TYPE),
    groupBy(
      action => action.bookId,
      action => action.bookId,
      bookId$ => bookId$.pipe(
        timeoutWith(15000, Observable.empty(),
        ignoreElements(),
      ),
    ),
    map(bookId$ => bookId$.pipe(
      exhaustMap(bookId => this.bookService.getOne(bookId)),
    )),
    mergeAll(),
  );
}