Promises demo

promises.js

(() => {

  const delay = (time=1000) => {
    return new Promise((resolve, reject) => {
      if(typeof time !== 'number') return reject(new Error('wrong type'));
      setTimeout(() => {
        return resolve(`waited ${time}ms`);
      }, time);
    });
  };
  
  const init = () => {

    delay(1000);
    delay(1000);
    delay(1000);

  };

  const init2 = () => {

    delay(1000)
      .then((message) => {
        console.log(message)
        return delay(1000)
      })
      .then(() => delay('test'))
      .then(() => console.log('done'))
      .catch(e => console.log(e));

  };

  init2();

})();