Maintainable JavaScript

Chapter 19. Automated Testing

Testing JavaScript has long been a pain point for developers. You want to test JavaScript quickly and easily, but there are so many browsers to test. The first solution was manual testing across all browsers, which meant creating an HTML file and manually loading it in various browsers to ensure that it worked. Though functional, this approach was too slow for practical use.

The next wave of JavaScript testing focused on command-line testing by stubbing out the browser environment. Several attempts were made to get JavaScript testing on the command line using Rhino and a fake browser environment. Some companies even developed browser profiles that could be loaded in with the promise of cross-browser testing. The unfortunate reality was that these stubbed browser environments didn’t do the job. Trying to recreate a truly unique environment by hand led to inconsistencies: your tests might pass in the “fake Firefox” but fail in the actual browser.

More recently, attempts have been made to use the actual browsers for testing. This approach typically involves using an HTML file to launch tests and then having an application load that file in the different browsers. Many of the tools mentioned in this chapter are still under development, but they all give you a good starting point for integrating browser-based JavaScript testing.

YUI Test Selenium Driver

YUI Test is the unit testing framework for the YUI Library. The most recent version of YUI Test is ...