JSQuestions/solutions/test-async-scheduler-pause.js

const TaskScheduler = require('./async-scheduler');

function wait(ms, label) {
  return () => new Promise((resolve) => {
    console.log(`${label} started`);
    setTimeout(() => {
      console.log(`${label} finished`);
      resolve(label);
    }, ms);
  });
}

(async () => {
  const scheduler = new TaskScheduler(1);

  scheduler.play();
  const p1 = scheduler.addTask(wait(200, 'A'));
  const p2 = scheduler.addTask(wait(50, 'B'));

  // Pause immediately; B should not start until play()
  scheduler.pause();

  await p1;
  console.log('p1 done');

  // Wait 100ms to see if B started (it shouldn't)
  await new Promise(r => setTimeout(r, 100));
  console.log('After wait, now play again');
  scheduler.play();
  await p2;
  console.log('p2 done');
})();