Use `queueMicrotask` to implement timer function

timer.js

function setTimeout(callback, delay, ...args) {
  const id = setTimeout._nextId++;
  const start = Date.now();
  function loop() {
    queueMicrotask(() => {
      if (!setTimeout._timers[id]) return;
      if (Date.now() - start >= delay) {
        delete setTimeout._timers[id];
        callback(...args);
      } else {
        loop();
      }
    });
  }
  setTimeout._timers[id] = [callback, ...args];
  loop();
  return id;
}

setTimeout._timers = {};
setTimeout._nextId = 1;

function clearTimeout(id) {
  delete setTimeout._timers[id];
}

function setInterval(callback, interval, ...args) {
  const id = setTimeout._nextId++;
  let start = Date.now();
  function loop() {
    queueMicrotask(() => {
      if (!setTimeout._timers[id]) return;
      if (Date.now() - start >= interval) {
        start = Date.now();
        callback(...args);
        loop();
      } else {
        loop();
      }
    });
  }
  setTimeout._timers[id] = [callback, ...args];
  loop();
  return id;
}

function clearTimeout(id) {
  delete setTimeout._timers[id];
}

function clearInterval(id) {
  clearTimeout(id);
}

timer_test.js

console.log(Date.now());
const a = [111, 222, 333];
const b = [444, 555, 666];
let count = 0;

// timeout
setTimeout((...args) => console.log(Date.now(), ...args), 12345, ...a);

// interval
const id1 = setInterval(
  (...args) => {
    count++;
    console.log(Date.now(), count, ...args);
    if (count >= 5) {
      clearInterval(id1);
    }
  },
  1000,
  ...b
);

// cancel the timer
const id2 = setTimeout(() => console.log("timeout"), 1000);
clearTimeout(id2);

/*
will output something like:

1681963305259
1681963306260 1 444 555 666
1681963307260 2 444 555 666
1681963308260 3 444 555 666
1681963309260 4 444 555 666
1681963310260 5 444 555 666
1681963317605 111 222 333
*/