example4.js

const click$ = Observable.fromEvent(button, 'clicks');
/**
 * Waits for 10 clicks of the button
 * then posts a timestamp of the tenth click to an endpoint
 * using fetch
 */
async function doWork() {
  await click$.take(10)
    .forEach((_, i) => console.log(`click ${i + 1}`));
  return await fetch(
    'notify/tenclicks',
    { method: 'POST', body: Date.now() }
  );
}