25 February 2021

Mutants to the rescue: How effective are your unit tests?


We write tests to tackle bugs, verify functionality and to ease maintenance. Using code coverage as our metric we might deem ourselves safe and our tests flawless. But how can we be sure that our tests are okay? The fact that tests cover the code doesn’t imply the code is working correctly. A missing assertion can be an opening for a plethora of bugs! In this talk we will enter the world of mutation testing. By generating mutants, i.e., faulty versions of your code, we measure how tests perform in detecting bugs. We will cover mutation tools, how they work, how to get started and how to integrate it in your builds.


Paco van Beckhoven

Paco van Beckhoven is a passionate software engineer that likes to challenge the world and the software around him. He works as a consultant for OpenValue where he helps customers build better software. A few years ago, he started speaking at conferences to entertain, and more importantly, educate visitors on various topics. After completing his master thesis on test effectiveness, he tries to get more people started with mutation testing.