Chaining sync with async functions

sync-async-chain.js

function giveLater (num) {
  return new Promise (function (resolve, reject) {
    setTimeout(function () {
      if (num) {
        resolve(num);
        return false;
      }

      reject('num is empty');
    }, 500);
  });
}

function numberToText (one) {
  return new Promise (function (resolve, reject) {
    if (!one) {
      reject('none');
      return false;
    }

    resolve('one');
  });
}

// Chaining sync with async functions 
giveLater(2)
  .then(num => num - 2)
  .then(numberToText)
  .then(txt => console.log(txt))
  .catch(err => console.error(err));