Diversity-aware mutation adequacy criterion for improving fault detection capability

Many existing testing techniques adopt diversity as an important criterion for the selection and prioritization of tests. However, mutation adequacy has been content with simply maximizing the number of mutants that have been killed. We propose a novel mutation adequacy criterion that considers the diversity in the relationship between tests and mutants, as well as whether mutants are killed. Intuitively, the proposed criterion is based on the notion that mutants can be distinguished by the sets of tests that kill them. A test suite is deemed adequate by our criterion if the test suite distinguishes all mutants in terms of their kill patterns. Our hypothesis is that, simply by using a stronger adequacy criterion, it is possible to improve fault detection capabilities of mutation-adequate test suites. The empirical evaluation selects tests for real world applications using the proposed mutation adequacy criterion to test our hypothesis. The results show that, for real world faults, test suites adequate to our criterion can increase the fault detection success rate by up to 76.8 percentage points compared to test suites adequate to the traditional criterion.