Golden Mutator Recommendation Based on Mutation Pattern Mining

Mutation testing is widely used in the research of evaluation and optimization of test set quality, and has been paid attention to the study of bug localization and fixing. But one inherent problem of mutation testing is huge computation cost. Selective mutation is an important method to reduce mutation testing cost. However, the existing selective mutation researches indicate that there is no universal selection strategy. This paper proposes a method which integrates with historical software data mining to recommend suitable mutator for program under test. The basic idea of the method is in the software version control system, any pair of nonfixed and post-fixed programs can be original program and mutant of each other. The edit performed during bug fixing contains mutators, and such mutator can guide buggy program to correct program, hence it is called Golden Mutator. The basic method is to compare the buggy files and the corresponding fixed files in the version control system, obtain historical faulty statements and their fix editing operations, thereby accumulating the bug-fix instance base, and then mining mutation patterns from it. Before mutating the target statement, we first find out faulty instances similar to the target statement, and use their fixing edits to match with the mutation pattern, so as to get the golden mutator applicable to the target statement. This paper uses Defects4j dataset in the test, verifies the accuracy of the proposed recommendation method, and further uses the method in bug localization. Compared to fixedly selected mutators, when applying the golden mutator recommended by using the proposed method, the average accuracy of bug localization is higher.