HOMAJ: A Tool for Higher Order Mutation Testing in AspectJ and Java

The availability of automated tool support is an important consideration for software developers before they can incorporate higher order mutation testing into their software development processes. This paper presents HOMAJ, a higher order mutation testing tool for AspectJ and Java. HOMAJ automates the process of generating and evaluating first order mutants (FOMs) and higher order mutants (HOMs). In particular, HOMAJ can be used to generate subtle HOMs, which are HOMs that cannot be killed by an existing test set that kills all the FOMs. Subtle HOMs can be valuable for improving test effectiveness because they can simulate complex and non-trivial faults that cannot be simulated with the use of traditional FOMs. HOMAJ implements a number of different techniques for generating subtle HOMs, including several search-based software engineering techniques, enumeration search, and random search. HOMAJ is designed in a modular way to make it easy to incorporate a new search strategy. In this paper we demonstrate the use of HOMAJ to evaluate the implemented techniques.