Notes From #isTDDDead?

I worried that I was going to find the discussion between DHH, Kent Beck and Martin Fowler annoying but I actually really enjoyed it. Well worth watching.

Kent & Martin’s responses seemed quite surprising to DHH who appears to have had a very dogmatic experience of TDD. The daily use of the guys that were influential in the popularisation of the techniques were more pragmatic than many people will have imagined.

I look forward to the next discussion where I think we’ll get into the meat of TDD.

I wrote a number of headline points for your enjoyment!

Kent Beck

  • If an idea is bad, find a cheap way to try it
  • Programmers have a right to feel confident about their code
  • TDD is one way to achieve confidence
  • Mixing techniques - some TDD, some not is totally fine - it’s powerful tool
  • TDD is often about trade offs
  • Don’t twist design to make it testable
  • Generally doesn’t mock anything
    • Mocking can couple you to implementation which too high a price
    • Repeatable feedback loop is far more important


  • Dogma in TDD circles is big problem (i.e. you must TDD 100% to be a ‘professional’)
  • Mocking forces unnatural structure, supporting tests instead of code
  • “Easy to test == better design” is a fallacy
  • Understandability is often compromised

Martin Fowler

  • TDD does not imply isolation or mocking
  • Self-testing code is one of the most important things to deliver - TDD is one approach and it has other benefits