A Gulp set up suited for most javascript projects

One of the most important things to think about when starting a new javascript project is which building tasks we want to create and automate to make sure we increase our development speed. This might not sound like a big thing, but it becomes evident when you think that a big portion of your time is spent doing building related tasks, like running unit tests, bundling components, transpiling less files, linting and so on.

I’ve done this process quite a few times now and I think I managed to get a pretty good automated building setup which definitely increases our productivity.

Depending on the javascript project you’re doing some of the tasks will vary. But I’ll explain that later.

But more to the point, if you’re thinking of starting a new React, Knockout, Angular or any of the fancy javascript libraries/frameworks projects, these are the bare minimum tasks you’ll have to automate:

  • Unit tests
    • Karma, webcomponents-tester and so on. This assumes you’re a TDD oriented developer, as you should 😉
  • Local development server
    • Local server that you’re going to use to test your application
  • Bundling
    • Bundles your application into small sized files for browser performance purposes.
  • Linting
    • To make sure your code doesn’t have errors or potential problems.
  • File Minification
    • To minify javascript, css and html files. This is normally an option on the bundling library, but for the sake of clarity I separate those.

These are, for me, the minimum building tasks every javascript project should have.

I’ll go through each one of them now, giving my preference about the library I normally use.

Unit tests:

Unit tests are one the most important parts of your application. They ensure your code does what is supposed to do and give you confidence to change your code.

If you’re not using a webcomponents library, my first choice to optimize your tests is Karma. Karma is maintained by the AngulaJs team, and it allows you to run your unit tests in an automated fashion.

gulp-karma is my favorite gulp task for this. It’s very simple to set up.

var gulp = require('gulp'); 
var Server = require('karma').Server; 

/* Run test once and exit  */ 

gulp.task('test', function (done) { 
            new Server(
                         configFile: __dirname + '/karma.conf.js', 
                         singleRun: true 

This code will run all your tests on your application. You can see more in the karma GitHub page. Combine karma with jasmine or mocha and you have all you need to unit test your application.

If you’re using webcomponents the web-component-tester library is the one to go. It was built by google for Polymer, but it can be used with other frameworks like x-tag and so on.

Local development server:

This is an absolute must have in every project. If you don’t want to spend all your time doing a release every time you change your code, a fast local development server is obligatory.

You have several options here, if you’re using webpack as your bundler, the webpack dev server is the best choice, is easy to configure and the hot module replacement is a very cool functionality. You can see more clicking here.

If you’re using requirejs or other bundlers, gulp-connect is one of my favorites. Is essentially a gulp plugin that allows you to use a webserver.


Modern web applications should be fast and responsive, and choosing the most suited bundler for your project goes a long way to achieve it. It helps to shrink  your application into one or more small chunks so that you can load them when your browser needs them. It also helps your application access node js libraries that would normally not work in the browser, only on the server.

Depending on the type of project you have, several options are available.

Requirejs is one of the oldest bundlers around and is still very used today. Although very good, I personally prefer webpack or browserify for the same type of projects. They are easy to set up, and webpack is so powerful that if you want you can basically substitute your gulp tasks with webpack plugins.

Webpack and browserify have the added benefit of allowing you to use node js libraries in the browser.

To see how you can use webpack with gulp click here, and for browserify click here.

If you’re using webcomponents the best and, as of the time of writing this post, the only bundler that supports html imports in an efficient manner is vulcanize developed by google for Polymer, but it works with other frameworks like x-tag and so on.


This is a very useful task to have if you don’t want to spend lots of time correcting errors in your javascript and doing potentially harm code.

gulp-jshint is perhaps my favorite due to the complete set of options you can use to configure it. You can also choose from a set of different reporters so you can choose the one you like the most.

var jshint = require('gulp-jshint');
var gulp   = require('gulp');

gulp.task('lint', function() {
  return gulp.src('./lib/*.js')

File Minification:

This is essential if you want to keep your release files small. Minifying html, css and javascript files can be done with several libraries, and bundlers like webpack or browserify can be set up with their own minification options.

But if you want to separate those tasks into different gulp tasks you can use gulp-cssnano, gulp-htmlmin and gulp-minify to minify css, html and javascript files respectively.



These are, for me, the bare minimum tasks you should have to automate/streamline your building process.

All these tasks can be done using grunt as well, but I prefer gulp because it’s more javascript-ish like 🙂