unit testing - RhinoMock vs. TypeMock vs. NUnit's Mocking?

Question

I am just starting to do Test Driven Development, and I am wondering the major differences between RhinoMock, TypeMock, and NUnit's built-in mocking?

Any information would be greatly appreciated!

Answer 1

TypeMock is a commercial product (meaning you'll have to pay for it) but will allow you to mock concrete objects - unlike RhinoMocks/NUnit/MoQ which can only mock an interface/abstract class. How it achieves this is borderline black magic, but it does some very clever things with the CLR.

This can be particularly useful when you use libraries in your project that don't use many interfaces. So you could, for example, use TypeMock to mock out a LINQtoSQL datacontext, or Sharepoint objects. However, if you are using TypeMock this is no excuse for bad design in your application.

As far as I'm aware, aside from minor syntax differences, most of the mocking frameworks have moved away from the old record/playback model. Commonly, you set up your mocks by writing expectations using a Fluent Interface.

Personally, I have only used MoQ and I <3 it.