Interview: materialize() an error as a Notification

The error should become a Notification of kind E, not a runtime failure.

1. Solve the task in the editor — no long theory.
2. Run the check and compare your output with the expected result.
3. Stuck? Open the solution and carry the approach into your own code.

const { throwError, materialize, map } = Rx;

const result$ = throwError(() => new Error('boom')).pipe(
  materialize(),
  map(notification => notification.kind)
);

result$.subscribe(value => console.log(value));