Is there an alternative to doing .subscribe() in map?

```
return this.http.patch<any>(URL, { test: true }).pipe(
    tap(_ => this.nextSomething$.next({})),
    filter(_ => this.filter),
    map(resp => {
      this.someObservable({ message: 'do' }).subscribe()
      return resp
    })
)

```

I tried doing switchMap and returning the previous response but my observable does not complete.

```
switchMap(prevResp => 
  this.someObservable({ message: 'do' }) }).pipe(map( _ => prevResp))
)

```

Thank you