What is wrong with Stubs for unit testing?

Question

I just watched this funny YouTube Video about unit testing (it's Hitler with fake subtitles chewing out his team for not doing good unit tests--skip it if you're humor impaired) where stubs get roundly criticized. But I don't understand what wrong with stubs.

I haven't started using a mocking framework and I haven't started feeling the pain from not using one.

Am I in for a world a hurt sometime down the line, having chosen handwritten stubs and fakes instead of mocks (like Rhinomock etc)? (using Fowler's taxonomy)

What are the considerations for picking between a mock and handwritten stub?

Answer 1

There is nothing wrong with stubs, there is room for stubs, mocks... and spies. All are "test doubles", but with different purposes as explained in Mocks and Stubs aren't Spies:

[...] Before moving on, I'd like to clarify and define some terms in use here, which I originally discovered in Gerard Meszaros' xUnit Patterns book.

• A Dummy Object is a placeholder object passed to the system under test but never used.
• A Test Stub provides the system under test with indirect input
• A Test Spy provides a way to verify that the system under test performed the correct indirect output
• A Mock Object provides the system under test with both indirect input and a way to verify indirect output

[...] And you can let this handy chart guide your decisions:

PS: Mockito - The New Mock Framework on the Block is worth the read too.