The Impact of Equivalent Mutants
- Mutation 2009
by
Bernhard J.M. Gruen, David Schuler, Andreas Zeller
Mutation '09: Proceedings of the 3rd International Workshop on Mutation Analysis, Pages 192-199, April 2009.
ISBN: 9780769536712
See also
More information is available at 10.1109/ICSTW.2009.37.
Abstract
If a mutation is not killed by a test suite, this usually means that the test suite is not adequate. However, it may also be that the mutant keeps the program's semantics unchanged---and thus cannot be detected by any test. We found such equivalent mutants to be surprisingly common: In an experiment on the Jaxen XPath query engine, 8/20 = 40% of all mutations turned out to be equivalent. Worse, checking the equivalency took us 15~minutes for a single mutation. Equivalent mutants thus make it impossible to automatically assess test suites by means of mutation testing.
To identify equivalent mutants, we are currently investigating the impact of a mutation on the execution: the more a mutation alters the execution, the higher the chance of it being non-equivalent. First experiments assessing the impact on code coverage are promising.
BibTeX Entry
@inproceedings{gruen-mutation-2009, title = "The Impact of Equivalent Mutants", author = "Bernhard J.M. Gruen and David Schuler and Andreas Zeller", year = "2009", month = apr, booktitle = "Mutation '09: Proceedings of the 3rd International Workshop on Mutation Analysis", location = "Denver, Colorado, USA", pages = "192--199", ISBN = "9780769536712", }