Mutation testing

Rafal Leszko is a Java developer at Google. Trainer and speaker at international conferences (Devoxx Morocco, Voxxed Days Thessaloniki). In the past he worked in a number of companies and scientific organizations: CERN, AGH University, Luxoft and more. His roles varied from a team lead, trainer, PhD researcher to developer, but one thing remains unchanged: he loves to be as active as possible, looks for challenges and has a lot of creative ideas (he was the one to introduce the Luxoft Lunch & Learn initiative).

How well tested is your system? How do you measure it? Code coverage can give you the answer, however can we trust our unit tests? Trust me or not, but I used to work for the investment banking industry in a big project where a lot of unit tests had no assertions (!). And yes… the coverage was very high.

Mutation testing is a method to check the quality of your unit tests and show more reasonable code coverage reports. In this session I will describe the idea of mutation testing and show a live example with the use of PIT Mutation Testing framework.