Real-life: switchScan() autosave state

Build autosave state where only the latest async operation matters.

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, switchScan } = Rx;

const result$ = of('a', 'b').pipe(
  switchScan((state, value) => of('saved:' + value), 'idle')
);

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