Mutation Testing
Monday, April 12, 2021By Goran Petrovic
History
It’s been a long-standing tradition of my team to organize hackathons twice a year. In weeks prior to the hackathon, the team gathers and brainstorms ideas for projects, ranging from improving the testing infrastructure or an existing process, to trying out a wild idea they’ve had for some time. Just before the hackathon, the team rates the accumulated ideas on a coolness-impact scale: how much fun does a project sound vs. how impactful could it potentially be; while impact is important, for hackathons, fun is non-negotiable. Then, engineers who are excited to work on some of the proposed projects subscribe and form teams. It was no different in the cold winter of 2013, where among the plethora of cool and wild ideas, one was to prototype Mutation testing.
For those who are not familiar with it, mutation testing is a method of evaluating test quality by injecting bugs into the code and seeing whether the tests detect the fault or not. The more injected bugs the tests catch, the better they are. Here’s an example:
