The link below is a guide on how to test WPF applications and
controls but has a lot of valuable content on API testing in
general
http://windowsclient.net/wpf/white-papers/wpf-app-quality-guide.aspx
Topics that are covered include the following:
- Information about the WPF programming stack.
- Information about different levels of testing, from API testing to integration to system testing.
- A list of available tools and related references.
Sample code is provided wherever applicable
