CJS (CommonJS, native olmayan modüller)

index.js

const utils = require('./utils.js');

console.log(`${utils.DEFAULT_SLEEP_MILLISECONDS} milisaniye uyuyalım `);
utils.sleep()
  .then(_ => {
    console.log(`3000 milisaniye uyuyalım `);
    return utils.sleep(3000);
  });

package.json

{
  "name": "moduller"
}

utils.js

const DEFAULT_SLEEP_MILLISECONDS = 1000;

function sleep(milliseconds) {
  return new Promise(resolve =>
    setTimeout(resolve, milliseconds || DEFAULT_SLEEP_MILLISECONDS)
  );
}

exports.DEFAULT_SLEEP_MILLISECONDS = DEFAULT_SLEEP_MILLISECONDS;
exports.sleep = sleep;