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

// usage
async function fn() {
  doStuff();
  // sleep for 1 second
  await sleep(1000);
  doAnotherStuff();
}

function doStuff() {
 console.log('foo');
}

function doAnotherStuff() {
 console.log('bar');
}