Faster mutation analysis with MeMu

Mutation analysis is a program analysis method with applications in assessing the quality of test cases, fault localization, test input generation, security analysis, etc. The method involves repeated running of test suites against a large number of program mutants, often leading to poor scalability. A large body of research is aimed at accelerating mutation analysis via a variety of approaches such as, reducing the number of mutants, reducing the number of test cases to run, or reducing the execution time of individual mutants. This paper presents the implementation of a novel technique, named MeMu, for reducing mutant execution time, through memoizing the most expensive methods in the system. Memoization is a program optimization technique that allows bypassing the execution of expensive methods and reusing pre-calculated results, when repeated inputs are detected. MeMu can be used on its own or alongside existing mutation analysis acceleration techniques. The current implementation of MeMu achieves, on average, an 18.15% speed-up for PITest JVM-based mutation testing tool.