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.