most basic API call

basic_effects.ts

@Effect()
fetchProducts: Observable<Action> = this.actions$.pipe(
  ofType<actions.FetchProducts>(actions.FETCH_PRODUCTS),
  switchMap(() =>
    this.productService.getProducts().pipe(
      map(products => new actions.FetchProductsSuccess(products)),
      catchError(() => of(new actions.FetchProductsError()))
    )
  )
);