A Formal Framework for Mutation Testing

Model-based approaches, especially based on directed graphs (DG), are becoming popular for mutation testing as they enable definition of simple, nevertheless powerful, mutation operators and effective coverage criteria. However, these models easily become intractable if the system under consideration is too complex or large. Moreover, existing DG-based algorithms for test generation and optimization are rare and rather in an initial stage. Finally, DG models fail to represent languages beyond type-3 (regular). This paper proposes a grammar-based mutation testing framework, together with effective mutation operators, coverage concepts and algorithms for test sequence generation. The objective is to establish a formal framework for model-based mutation testing which enables complementary or alternative use of regular grammars, depending on the preferences of the test engineer. A case study validates the approach and analyzes its characteristic issues.