Phil Bennett has a new post today talking about a way that you could use dependency injection in your testing, making it easier to work your system by using stubs, fakes and mocks.
Dependency injection is a simple design pattern that provides several benefits, one of which is the ability to vastly improve your unit test suite. In this post I am going to be looking at how this is done and how it relates to certain testing methodologies.
He talks some about the refactoring of an application to allow for easier dependency injection and how, while easier, can still make it difficult to abstract out things like database functionality. Instead, he suggests creating "fake" classes that model the behavior of the needed dependency. He shows examples of each type - a fake, stub and mock - and talks some about the differences between each (and situations one might be used over the other).