const order = [];
order.push('start');
setTimeout(() => { order.push('timeout'); console.log(order.join(',')); }, 0);
Promise.resolve().then(() => order.push('promise1'));
async function foo() {
  order.push('foo start');
  await null;
  order.push('foo end');
}
foo();
Promise.resolve().then(() => order.push('promise2'));
order.push('end');