The Purpose of Mocking

Question

What is the purpose of mocking?

I have been following some ASP.NET MVC tutorials that use NUnit for testing and Moq for mocking. I am a little unclear about the mock

Answer 1

One other answer :

• Stub = fake objects to be able to run your test without the entire real context

• Mock = fake object to record the interaction of your component and verify theses interactions

You can have several stubs in one test but only one mock because if you have more than one mock you certainly test more than one feature (and it defeat the purpose of the test-one-thing principle).

To go beyond the basics, Mocks are more behavioral verification than the traditionnal state verification of the test where you check the state of your component after acting on it (Arrange,Act, Assert with Mocks it is more Arrange, Act, Verify) :

State verification Assert.AreEqual(valueExpected,mycomponent.Property); Behavioral verification : myMock.WasCalled(MyMethod);