WatiN

Yes - you can use WatiN and Visual Studio Team System!  Simply create a brand new Unit Test within your project and use WatiN within the test methods.  The only catch is if you get an error that looks like this : 

The location of the file or directory ___ is not trusted.  To resolve this I needed to right click on BOTH WatiN.Core.dll and Interop.SHDocVw.dll and click the "Unblock" button at the bottom.  After that I needed to rebuild my project before the tests would run.

The following class can be used to override the standard IE object in WatiN to run specific tests after every page load.  For example, in Drupal this class can be used to make sure that no error messages appear on any page during the test run.
 

In my previous post, I discussed the basics of using Gallio, MbUnit, and WatiN to test web applications.  In the previous example you could continue to add tests to the class by creating additional test methods and marking them with the test attribute.  However, you could not guarantee what kind of order those tests would run in.  Fortunately, MbUnit/Gallio is a flexible enough framework to allow you to create orderd test suites which is a common need for functional testing.
 

This post is about three remarkable open source testing tools.  WatiN, a .NET based web application testing framework can be used to drive the Internet Explorer, Firefox, and even Chrome web browsers.