Synchronous and asynchronous python-like sleep function

sleep.js

// Sycnhronous python-like sleep function
const sleep = (ms) => {
  const start = new Date().getTime();
  const expire = start + ms;
  while (new Date().getTime() < expire) {
    // spinning...
  }
};

// Asynchronous sleep
const sleep = time => new Promise(_ => setTimeout(_, time))