The Unit Test projects use MS-Test by default in Visual Studio 2012. It is Microsoft’s unit testing framework that also allows you to use third party unit testing framework such as NUnit, MbUnit, and xUnit.NET. This will allow you to perform any unit testing of your choice and still use Visual Studio IDE to run tests.
This article will show you the capabilities of Visual Studio 2012 and its features. You may already know that Visual Studio 2012 will let you use third-party testing frameworks for your applications and in this lecture, we’ll teach you how to use NUnit to for unit testing.
Read the rest of the tutorial here:Â http://www.codeguru.com/csharp/.net/using-nunit-with-visual-studio-2012-unit-test-projects.htm