promise.js

setImmediate(() => console.log(1));
console.log(2);
Promise.resolve().then(() => setTimeout(() => {
  setImmediate(() => console.log(3));
  console.log(4);
  Promise.resolve().then(() => setImmediate(() => {
    setImmediate(() => console.log(5));
    console.log(6);
    Promise.resolve().then(() => {
      setImmediate(() => console.log(7));
      console.log(8);
    });
  }));
}));