Let’s Code: Test-Driven JavaScript

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

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Latest Live Episodes

  1. Testing Touch Events on iOS 8

    Wed, 29 July

    Our CSS tests caught a minor incompatibility between Chrome Mobile and our other devices. We walk through the fix, then figure out what’s causing our touch tests to fail on iOS 8. When that’s fixed, the chapter is done. Ship it!

  2. A Mutual Incompatibility

    Mon, 27 July

    Testing touch events involves calling the initTouchEvent() method. Without it, we couldn’t simulate browser touch events. Android and iOS both support that critical method, but they have different parameter ordering! We figure out how to use feature detection to get our tests working on both browsers.

  3. Testing Touch Events on Android

    Wed, 22 July

    We have an Android emulator up and running, but our tests are failing. How do we fix them? We start by running a manual test to confirm that the production code works, then dive into the intricacies of generating touch events in our tests.

Latest Specials

  1. JavaScript Gotchas, Part II

    Fri, 31 July

    We continue our detailed walkthrough of JSHint’s options and common JavaScript errors they help catch. We finish up with a brief discussion of the risks of floating-point arithmetic. That ends our chapter on code safety.

  2. JavaScript Gotchas, Part I

    Fri, 24 July

    There’s some dark corners of JavaScript that are best avoided. As long as you do avoid them, JavaScript is a pleasure to work with. In this episode, we look at common JavaScript gotchas and set up JSHint to automatically warn us when we stray off the path.

  3. Lint

    Fri, 17 July

    We start a new chapter focused on safe coding practices, with an emphasis on static code analysis with Lint. We look at the popular Lint options for JavaScript and choose JSHint. We install JSHint and walk through a few options for incorporating it into our automated build.

An in-depth screencast about
Test-Driven JavaScript

You've taught me a lot this past year and have
been better than a teacher, a true mentor.
Jason Weden
I’m completely new to TDD and this is by far
the most comprehensive TDD for JS... your videos are
a breath of fresh air!
Adam Brodzinski
This is a gold mine... This will help a lot in my day job.
Timothy Myers
Love what you're doing. It's helped out our
team tremendously here at Sevenly.
Scott Corgan
I’m delighted with LCJ. It’s interesting and informative, and the
candid way you think aloud makes it personal and engaging.
You’ve done a terrific job.
Crispin Bennett

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 butt 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 15 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 test against multiple browsers and platforms, including iOS, and we use Node.js on the server.

All videos are DRM-free, available for streaming or download, and all source code is included.

The Videos

The series consists of four main channels. The “Recorded Live” channel focuses on real-world development, warts and all. It’s meant for experienced programmers.

If you’re a new developer, the “How To” channel is for you. It’s meant for beginners who have recently learned to program and are ready to start their professional career.

The “Lessons Learned” channel provides concise reviews of key topics, such as continuous integration, test-driven development, and build automation. It’s great for review and reference.

Advanced programmers will enjoy “The Lab”, our channel focused on exploring new tools and ideas.

Release Schedule

New videos are published every week. At the time of this writing, a new “Recorded Live” episode is released every Monday and Wednesday, and a new “How To” episode is released every Friday.

When the current “How To” season finishes, we will probably return releasing a new “Lessons Learned” or “The Lab” episode on the first Friday of every month.

“Recorded Live” and “How To” episodes are about 15 minutes long. “Lessons Learned” videos are typically about 15-30 minutes long, and episodes of “The Lab” tend to be about an hour.

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.