Towards practical application of mutation testing in industry — Traditional versus extreme mutation testing

Mutation testing is a technique that changes code instructions to assess the quality of automated software tests. Industry has not broadly adopted because execution and analysis times are too long considered worth effort. To change this, variation called “extreme mutation testing” emerged, which mutates whole methods instead instructions. The extreme variant trades accuracy for speed gains also provides pre-analyzed results. In this study, we aim analyze both techniques on their granularity levels, look benefits when combining them, find motivations developer considers killing mutants. For that, conducted case study in company from semiconductor industry. We mutated large Java project tested by more than 11,000 unit tests, analyzed results, manually inspected 1000 mutants, focus group with five developers software. Among other provide distribution traditional across mutants as well qualitative coding results our mutant inspection transcript. conclude approach can be similarly strategically applied one target mostly related.