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PIT-HOM: an Extension of Pitest for Higher Order Mutation Analysis

Mutation testing is a well-known, effective, fault-based testing criterion. First order mutation introduces defects in the form of a single small syntactic change. While the technique has been shown to be effective, it has some limits. Higher order mutation, where the faults introduced include multiple changes, has been proposed as a way to address some of these limits. Although the technique has shown promising results, there is no practical tool available for the application and study of higher order mutation on Java programs. In this paper we present PIT-HOM, an extension of Pitest (PIT) for higher order mutation. Pitest is a practical mutation analysis tool for Java, applicable on real-world codebases. PIT-HOM combines mutants in a same class to create higher order mutants of user-defined orders, it runs the mutants and reports the results in an easy to process format. We validate PIT-HOM using two small Java programs and report its performance as well as some characteristics of the mutants it creates.