Gulp task system and Promises

Gulpfile.js

/**
 * Bluebird allows us to promisify existing Node.js
 * technologies. So fs.writeFile and fs.readFile
 * are usable with Promises.
 * 
 * `fetch` fetches Ressources. This code fetches
 * jQuery, and saves the responses body in a file
 **/

var gulp = require('gulp');
var Promise = require('bluebird');
var fs = Promise.promisifyAll(require('fs'));
var fetch = require('node-fetch');

gulp.task('fetch', function() {
  return fetch('http://code.jquery.com/jquery-2.1.4.min.js')
    .then(function(data) {
      return data.text();
    })
    .then(function(body) {
      return fs.writeFileAsync('jquery.js', body);
    });
});

Cool :-) I'm still new to all the Node 4 stuff ;-) With streams, I'd use the gulp API then.