27 November 2008

Only mock types you own (revisited)

There was a brief discussion on the JMock mailing list recently where we helped out a new user. In the process, we noticed that he was mocking Java Set, which we tend to avoid, because it's not a type that we own—it's not in the domain of the problem we're trying to solve. The way I put it was,

We see a lot of people using, for example, List<House> when what they actually mean is Street. We try to use types we own that represent concepts in the domain, rather than built-in or library types which we keep for implementing these domain types. If the domain types are defined in terms of roles, then they're often appropriate for mocking.

Isiah followed up with an old post of his own.

I think we have a satisfied customer:

Thank you Steve and Isiah, I think I just took a large step in the world of TDD.

It's nice when that happens...

More example, reworking the process

We've posted some more chapters from the long worked example. We've also been reworking the material on the Process of TDD. Take a look, and comments are always welcome.