Angular && RXJS http call error handling in observable subscription

 https://blog.angular-university.io/rxjs-error-handling/

const http$ = this.http.get<Course[]>('/api/courses');
	http$
	.pipe(
	map(res => res['payload']),
	catchError(err => {
	console.log('caught mapping error and rethrowing', err);
	return throwError(err);
	}),
	finalize(() => console.log("first finalize() block executed")),
	catchError(err => {
	console.log('caught rethrown error, providing fallback value');
	return of([]);
	}),
	finalize(() => console.log("second finalize() block executed"))
	)
	.subscribe(
	res => console.log('HTTP response', res),
	err => console.log('HTTP Error', err),
	() => console.log('HTTP request completed.')
	);