We want to understand how to go about catching an Observable error, thus we need an Observable that we can subscribe to that will trigger the error.
Approach
Use RxJs throwError:
import { throwError, Observable } from 'rxjs';
const catchMeIfYouCan:Observable<string> = throwError('Catch me if you can')
catchMeIfYouCan.subscribe(
()=>console.log("Next handler will not execute"),
(e)=>console.error(e),
()=>console.log("Completion handler will not execute"))
Only Catch me if you can is logged, indicating that the Observable errored out.