Interview: mergeAll() flatten

Flatten a stream of inner Observables with mergeAll.

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 { of, mergeAll } = Rx;

const result$ = of(of('x', 'y'), of('z')).pipe(
  mergeAll()
);

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