There is a big difference between "true" TDD and simply writing the tests before you write the code. According to the TDD evangelism I've seen, it means (1) wr

There is a big difference between "true" TDD and simply writing the tests before you write the code. According to the TDD evangelism I've seen, it means (1) writing tests one at a time, which should fail at the time that they're written; (2) after adding each test, write code that will past that one test while being deliberately ignorant of any requirements that will show up in future tests; (3) refactor, rewrite, etc, as needed as new tests are added. I suppose this could be meant to mimic how code in long-lived systems evolves as requirements are discovered and changed. Or it could be meant to promote awareness of you-aint-gonna-need it and reduce over-engineering. Either way it also will necessarily cause extreme short-sightedness and err strongly on the side of under-engineering, and in the case of mimicking natural code evolution it would be an example of cargo-cult thinking.