Interview: concatAll() a queue of inner streams

Flatten the inner Observables sequentially with concatAll.

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, concatAll } = Rx;

const result$ = of(of('A', 'B'), of('C')).pipe(
  concatAll()
);

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