As we have already commented, there are specific features in Silverlight, which make certain classes unable to be tested with the technique mentioned previously, due to particular dependencies of their framework, or because of the use of asynchronous features or visual elements. To solve this issue, there are specific libraries for testing in Silverlight, as follows:
Silverlight Unit Testing (SilverlightUT): This was originally developed by Microsoft to try the Silverlight Toolkit, which also includes it. When the Toolkit is installed, the templates are integrated with Visual Studio 2010. Tests are executed on the browser, within Silverlight.
SilverUnit : With a higher level of isolation, this library does not require a browser. So it is more automatable, yet allows the testing of visual elements.
Selenium-Silverlight: This is an automation web library extended to support Silverlight.
AgUnit: This is a plugin for ReSharper that allows you to run and...