At the recent 2014 Esri Developers Summit in Palm Springs, Dave Bouwman, David Spriggs, and I presented on Testing Tools & Patterns for JavaScript Mapping Apps.
The video, slides (PDF), and links to related resources from that talk are all now available at the GitHub repository we created for the talk.
Personally, I think Dave Bouwman’s introductory section on the how and why of JavaScript unit testing is as good as any presentation or book (mapping or no) that I’ve seen or read on the subject and is definitely worth a watch.
Beyond that, if you’re interested in the mechanics of testing mapping apps with any of the frameworks we cover (the Intern, Jasmine, Karma, etc) there are plenty of resources to get you going.