Sleep function in JavaScript (need node v7.10+, borrowed from https://twitter.com/samccone/status/859777976199659521)

sleep.js

async function sleep (dur) {
  return new Promise((resolve, reject) => {
    setTimeout(() => resolve(), dur);
  });
}

async function yay () {
  console.log('i am sleepy');
  await sleep(5000);
  console.log('i need more sleep');
  await sleep(10000);
  console.log('all rested');
}

yay();