An example of the cat HTTP request function using promises.

cat-promise-example.js

const path = require('path');
const http = require('http');
const URL = require('url').URL;

const url = new URL('http://random.cat/meow');

/* getCat function that creates an HTTP request (asynchronous) and 
*  supplies the data of the cat picture through a promise. 
*/
function getCat() {
  return new Promise((resolve, reject) => {
    http.get({
      hostname: url.hostname,
      path: url.pathname,
      pathname: url.pathname
    }, (res) => {
      res.setEncoding('utf8');
      let rawData = '';
      res.on('data', (data) => {
        rawData += data;
      });

      res.on('end', () => {
        /* Runs the resolve function when the request ends. */
        resolve(JSON.parse(rawData));
      });
      res.on('error', (err) => {
        console.log(err);
        /* Runs the reject function if an error occurs. */
        reject(err);
      });
    });
  });
}

/* Get cat function that returns a promise. */
//ES6
getCat().then(data => {
  console.log(data);
});
//ES5
getCat().then(function (data) {
  console.log(data);
});