How to detect inside a stream if the subscribe defined an error handler

Suppose I have the following

function getData() {
    return this.http.get('data');
}

...

getData().subscribe({
   complete: () => {
      this.closeDialog();
   });
}

Not tested, but I think this should work. However, the this.http call can throw an error. That can be fixed as follows

getData().subscribe({
   error: (err) => { this.showNotification(err) },
   complete: () => { this.closeDialog() }
});

or I could catch it inside getData

 function getData() {
    return this.http.get('data').pipe(catchError(err => {
        return of({});
    });
}

What I would like to do is:

1. If the subscribe defines an error handler, don't catch the error inside getData
2. If the subscribe doesn't define an error handler, catch the error inside getData

Is this possible? If not, I'm all ears to other suggestions/solutions!