Let’s Code: Test-Driven JavaScript

James Shore presents a fascinating screencast
on rigorous, professional JavaScript development

Browse the Catalog

Latest Live Episodes

  1. A Font Normalization Algorithm

    Wed, 19 Nov

    An investigation into font loaders leads to the question: When are insufficient tests good enough? We consider the question, then move on to an algorithm to normalize the three different font-family results we’re getting from our test browsers.

  2. @font-face

    Mon, 17 Nov

    We can test built-in fonts. What about web fonts using @font-face? We head over to Font Squirrel, choose a font, and get it working. It doesn’t work the way we expect, though—or rather, it works when it shouldn’t. Even when we make a mistake and fail to load the font, our tests say it’s present.

  3. font-family

    Wed, 12 Nov

    We start a new chapter that’s all about fonts. We’re going to look at built-in fonts, downloaded fonts, and even font services like TypeKit… and test-drive as much of it as we can, of course. We start with a review of our progress so far, then get basic font-family support tested and implemented.

Latest Specials

  1. Front-End Frameworks: AngularJS (Part I)

    Fri, 7 Nov

    AngularJS is a hugely-popular framework for web applications from Google. It’s known for its two-way binding and automatic dependency injection. But does it live up to our standards of maintainability and long-term reliability? We take a close look in this two-part series. First: AngularJS fundamentals, including controllers, directives, modularity, and testing.

  2. Quixote: CSS Unit Testing

    Fri, 3 Oct

    On the Recorded Live channel, we’ve been working on a proof-of-concept suite of CSS unit tests. The concept’s been proven. Now it’s time to turn that work into a general-purpose open source library: Quixote. I’m conducting a virtual hackathon October 13-16 starting at 10am PDT (GMT-7) to build the library. Join us!

  3. Front-End Frameworks: React (Part II)

    Fri, 5 Sep

    We conclude our look at React, the front-end library from Facebook. In this part, we investigate React’s architecture and design constraints by building a real app. How well does React deal with architectural approaches that it wasn’t designed for? How does it coordinate far-flung components? What about lock-in, complexity, and testing? We answer it all.

An in-depth screencast about
Test-Driven JavaScript

What our viewers are saying:
I will be using it as *the* goto reference for
any JS development for some time to come.
It has the right number of details that you don’t get by
reading book but only working with exceptional people.
I like the variety of technologies used and the
complete integration of them shown together.
I like seeing *all* aspects of the development:
the dead ends, the surprises, the wins, etc.
Quality is excellent, and I love that I can
download them and not have to stream them.

JavaScript Needs Test-Driven Development

If you’ve programmed in JavaScript, you know that it’s an… interesting… language. Don’t get me wrong: I love JavaScript. I love its first-class functions, the intensive VM competition among browser makers, and how it makes the web come alive. It definitely has its good parts.

It also has some not-so-good parts. Whether it’s browser DOMs, automatic semicolon insertion, or an object model with a split personality, everyone’s had some part of JavaScript bite them in the ass at some point. That’s why using test-driven development is so important.

What is Test-Driven Development?

Test-driven development (TDD) is a technique for ensuring that your code does what you think it does. It’s particularly relevant for JavaScript, with its cross-browser incompatibilities and hidden gotchas. With TDD, you express your intentions twice: once as a test, and once as production code. If the two approaches don’t match, your tests fail, and you’ve caught a bug.

TDD is a great way of catching the majority of programming errors. It’s not perfect, of course—in particular, it can’t tell you when your assumptions are wrong—but it’s very good at catching the kinds of bugs JavaScript is prone to.

Who am I?

I’m James Shore. I’ve been building applications using test-driven development and other Agile techniques for over 13 years. I’m a recipient of the Agile Alliance’s Gordon Pask Award for Contributions to Agile Practice and I wrote a book called The Art of Agile Development.

What You Get

This screencast series focuses on rigorous, professional web development. That means test-driven development, of course, and also techniques such as build automation, continuous integration, refactoring, and evolutionary design. We support multiple browsers and platforms, including iOS, and we use Node.js on the server. The testing tools we’re using include NodeUnit, Mocha, expect.js, Karma, and PhantomJS.

All videos are DRM-free, viewable on the web and downloadable, and all source code is included.

The “Live” Channel

The series consists of three main channels. “Recorded Live” episodes are a live recording of an application as it’s developed, with commentary. I edit out dead-ends and time spent in research so each episode is focused and meaningful. Each “Live” episode is about 15 minutes long and comes out twice per week, on Monday and Wednesday.

The application itself is a real-time multi-user drawing application, developed from scratch and continually enhanced in each episode.

Monthly Specials

In addition to the “Live” episodes, you also get a special “Lessons Learned” or “The Lab” episode every month.

“Lessons Learned” episodes are for people wanting a refresher, a quick reference, or who simply want to catch up. They provide a distilled look at a specific topic, such as automating Lint, testing a Node.js server, or automating cross-browser testing.

“The Lab” is about exploration and experimentation. These episodes examine topics that don’t fit into the other two channels.

I have learned so much more than I expected.
I really enjoy your approach to screencasting and
wish the series wouldn’t end some day.