[adambender]

After 10+ years working on testing practices inside Google, I have found that even the most obvious practices somehow get ignored or misunderstood. As with a lot of programing practices, for every person that has thought deeply about why the practices exists, there exist many many more who just apply the practice as a matter of course (eg mocking, dependency injection, micro services, etc).

It might be useful to provide a little more context for why I wanted to write this in the first place - Over the last 15 or so years we have been tremendously successful at getting folks to write tests. And like any system, once you remove a bottleneck or resource constraint in one place, you inevitably find one somewhere else. In our case we used to take running our tests for granted, but now the cost of doing so now has actual cost implications that we need to consider. I also observed some in internal discussions that had become a little to strident about the absolutes of one kind of test or another, and often in such a way that treated terms like "unit" or "integration" as a sort of universal categories, completely ignoring the broad, practical implications we have bound together into a few shorthand terms.

My goal when trying to develop this idea was to find a way to succinctly combine the important set of tradeoffs teams should consider when thinking, not about a single test, but their entire test suite. I wanted to create a meme (in the Dawkin's sense) that would sit in the background of an engineer's mind that helped them quickly evaluate their test suite's quality over time.