In one point of the discussion, there is a discussion about failures. The first story Llewellyn tells about failure is having five developers work for a week on programming when the end result of that task is equivalent to 6 hours of manual one-time work. The story is about asking of value in advance. Good lesson.
I have had the privilege of many discussions about unit testing and test automation with Llewellyn. The story reminded me of my perception: with test automation, I often bring forth the discussion about real need of repeating and value of spending hours and hours in automating something I don't care to repeat but could do in seconds. But while the value seems like a relevant driver for me, the point that I feel we end up with is doing things anyway just to learn if (and how) it can be done. Value of learning (and solving a challenge) goes over the value of using time on testing.
There's a rule for unit testing Llewellyn cites a lot: Test until bored. As long as you are contributing to the overall value that testing could provide immediately or in long term, you are not bored. As long as you are learning, you are not bored.
I'm puzzled with this: I can always name many things I intentionally don't test, as there is never enough time for testing it all. I'm painfully aware of the opportunity cost of writing documentation or creating test automation over testing just a little more from the endless list of ideas.
I see my teams developers approach unit testing avoidance with similar arguments that I use on selecting what is worthy of automation on system or feature level. It makes me appreciate the approach test-oriented programmers like Llewellyn take: the challenge of learning is worth the effort.
But I still can't help but wonder: why the same rule of overall value wouldn't hold in the domain of testing as for other problems we solve with programming?
- adding the first test enables us to add more tests like that with a cheaper cost - repeatability is the solving a particular problem in a particular way in addition to repeating the same test by means of automation
- if we don't automate because of cost-value discussion (with unknown cost), it's just another trick in the bag of excuses for us
- we don't really know to estimate the cost before we have a solution, until then we can only discuss if the problem is worth solving at all
- the discussion about the unknown cost can take more effort than just doing it