When applying the MVVM pattern, the UI-logic is placed in ViewModels. A key advantage of such a ViewModel is that it is highly testable. In this course, WPF and MVVM: Test Driven Development of ViewModels, you'll learn the specifics of unit testing within MVVM. You'll discover how to create and run unit tests in Visual Studio with the popular testing framework xUnit, and how to write testable ViewModels by moving out typical dependencies like data access logic, event aggregator, modal dialogs and more. Next, you'll be taught how to mock/fake these dependencies in your unit tests by using the mocking library, Moq, as well as inject the dependencies into your ViewModels with a dependency injection framework called Autofac while running your application. Finally, you'll build and unit-test the ViewModels for an MVVM app called FriendStorage from 'empty class' to final by using test-driven development. By the end of this course, you'll understand how to develop your ViewModels through testing in order to create better apps than ever.