[aslakhellesoy]

You and I have very different opinions on the purpose of TDD. You're presuming it's a design technique - many do. For me, TDD is all about validating a design in a way that gives me faster and better feedback than if I were just coding. I design the code before I write the first test. In fact, my test is derived from the design.

First I sketch a rough implementation design on a napkin or whiteboard. I don't worry about making it perfect, just good enough to create an initial mental model, and perhaps discuss it with someone.

Then, I write a test to express how I would like to interact with a small area of an implementation of this design, typically by calling a function or method and expressing a desired outcome.

I use the feedback from the test to drive out some simple code that resembles the design I sketched. If at any point this becomes hard, I take that as a clue that my napkin design can be improved, so I go back and tweak it.

Then I start over again. This is a quick cycle, typically 10 minutes or so. I get constant feedback on my design as well as my implementation.

I don't design code with TDD. I design code exactly the same way people who don't to TDD do it. Through intuition and experience. This is a skill, not a process. I only write tests to validate my design (not my implementation). Of course, because they are tests, they automatically validate my code as well, but that is not why I am doing it. If I only cared about testing, I might as well write them last.

More often than not my designs are imperfect, but by doing TDD I always improve them significantly, with relatively little time and effort.

It's taken me 15 years to get decent at it, and I'm still learning new techniques and abandoning others. There are many tricks to be learned. I usually only TDD when I care about the design. Quite often I don't, and then I just hack. I'm simply making a choice between going very fast now or going reasonably fast in a year. I haven't found a way to do both yet.