Unit Test Basics

The unit test framework that you use and Visual Studio IntelliSense will guide you through creating unit tests for a code project. To run in Test Explorer, most frameworks require that you add specific attributes to identify unit test methods. The frameworks also provide a way—usually through assert statements or method attributes—to indicate whether the test method has passed or failed. Other attributes identify optional setup methods that are at class initialization and before each test method and teardown methods that are run after each test method and before the class is destroyed.

The AAA (Arrange, Act, Assert) pattern is a common way of writing unit tests for a method under test.

• The Arrange section of a unit test method initializes objects and sets the value of the data that is passed to the method under test.
• The Act section invokes the method under test with the arranged parameters.
• The Assert section verifies that the action of the method under test behaves as expected.

http://msdn.microsoft.com/en-us/library/hh694602.aspx#BKMK_Creating_the_unit_test_projects