How common is the of(undefined) pattern in angular, and what are its benefits?

I recenlty was reviewing a project where Angular observables are heavily utilized across both components and services, as to “reactive programming approach”. I’ve noticed the use of of(undefined) in many observable chains.

While I understand that of(undefined) serves as an initial trigger in observable streams, I’m curious about how widespread this approach is among developers and whether it’s considered a best practice for specific scenarios.

Here’s an example to illustrate how this is used:

private doAction(): Observable<void> {
  return of(undefined).pipe(
    switchMap(() => {
      // perform actions
      return of(undefined);
    }),
    catchError((err) => {
      console.error('Error occurred:', err);
      return of(undefined); // Handle error by returning another undefined observable
    }),
    finalize(() => {
      // cleanup code here
    })
  );
}