This is another in Robert's Getting Started series, where he provides an introduction to a topic that everyone knows about but not everyone is actually doing (or doing enough of). In part 1 of this 3 part series, Robert showed how to get started with unit testing in Visual Studio. In this episode, he shows how to write unit tests that test the UI interactions in a XAML application. He then shows how to create data-driven tests and how to perform a code coverage analysis to determine what parts of your code are being covered by unit tests.
You can find the sample code and demo scripts for the entire 3 part series here.