Ngrx效果具有多个动作

Question

如何在http请求之前添加操作？我想在请求之前运行TEST_INC ...，然后在http请求之后运行TEST_DEC

 @Effect()
 acadDomain$: Observable<Action> = this.actions$.pipe(
  ofType('INIT_ACADEMY_DOMAIN'),
  // I want here to apply action "TEST_INC"
  mergeMap((action: any) =>
     this.http.get('https://DOMAIN/settings.json').pipe(
        switchMap((data) => [
           { type: 'INIT_ACADEMY', payload: data },
           { type: 'TEST_DEC' }
        ])
     )
  )
);

仅供参考：（rxjs 6）