Testing Numbs Us to Our Loss of Intellectual Control

Abstract

It seems that today, with all of our tests, we allow the code to grow woolly and complicated in ways that, in the past, with no automated regression tests, we never could have tolerated. We were forced to keep the code simple because if we didn't, the complexity of the special cases wouldn't fit in our heads. This leads me to the following idea, which I will dig into in the rest of this article: Software teams need a healthy balance of both intellectual control, which comes from reasoning, and statistical control, which comes from testing. Complexity is the enemy of reasoning; efforts to maintain intellectual control tend to push complexity down. In my experience, many teams let their intellectual control atrophy and then compensate with more testing. This approach works for a while, but without intellectual control to keep complexity down, progress becomes slower and more difficult. Once lost, intellectual control is expensive to recover, so the teams find themselves in a local maximum they cannot escape.