TDD, it's not about testing.

I subscribed a lot of blogs and it seems in their world, TDD is something that needs not to explain, at least the name it self is as clear as the name of "Unix". But sadly I discovered this might only be true in some software house, but not in most of the IT departments in normal companies.

Anyway, I found some good explanation about TDD, which is very insightful. TDD is not about testing, it's about design. The tests to guarantee quality, to weave the safe-net is a valuable byproduct.

I recall one of the API for a report generator. The report format looks complex. I decided to design a model for the report, and once the model is done, generating the report should be straight forward. I started with some tests to generate part of the data the report needs, this forced me to think about the model structure and API in another angle. And finally it turned out a very different, if not completely different, but simple API. I reviewed it and was glad about its elegance. I would not be able to design such a nice API if I test after!