First impressions: mutation testing

engineering-management.space

I was curious about Mutation Testing and the value we can take out of it. So I took an hour to play with it and try to understand it better. What’s mutation testing? In mutation testing we have a program that changes our application’s code and then runs the tests. If no tests fails, it means that we may have a problem. In practice this means that we don’t have a full coverage on that code. This is not about the typical 100% code coverage metric. Because we can have some code that is 100% covered and still find problems with mutation testing.