The Plugin adds support for command-line and in-browser JS unit tests to your Rails app. It bundles several great tools together in a convention-over-configuration, Rails-like way.
Is a test tool for web applications that tests run directly in a browser just as real users do. Supports Internet Explorer, Mozilla and Firefox on Windows, Linux, and Macintosh. No other test tool covers such a wide array of platforms.
9. Watir (pronounced water)
Is an open-source (BSD) family of Ruby libraries for automating web browsers. It allows you to write tests that are easy to read and maintain. It is simple and flexible.