FP-example-reformatted.js

export const scheduleEpic = action$ => action$.pipe(
  ofType(FETCH_SCHEDULE_REQUEST),
  debounceTime(300),
  switchMap(({ payload }) => {
    return ajax
      .getJSON(`${API_URL}/AvailableSeatStatusList/${payload.OriginStationID}`)
      .pipe(
        map(response => ({
          ...payload,
          availableSeatTable: availableFormater(response[0], payload.DestinationStationID),
        })),
        catchError(error => of({ type: FETCH_SCHEDULE_FAILURE, error: error.xhr.response })),
      )
  }),
  switchMap(({
    availableSeatTable,
    OriginStationID,
    DestinationStationID,
    TrainDate,
  }) => {
    if (!availableSeatTable.length) {
      return [fetchSuccess(availableSeatTable)]
    };

    return ajax
      .getJSON(`${API_URL}/DailyTimetable/OD/${OriginStationID}/to/${DestinationStationID}/${TrainDate}`)
      .pipe(
        map((response) => {
          const timeTable = timeTableFormater(response);
          return fetchSuccess(leftJoin(availableSeatTable, timeTable));
        }),
        catchError(error => of({
          type: FETCH_SCHEDULE_FAILURE,
          error: error.xhr.response,
        })
      ),
    );
  }),
);