Interface Mutation: an approach for integration testing

The need for test adequacy criteria is widely recognized. Several criteria have been proposed for the assessment of adequacy of tests at the unit level. However, there remains a lack of criteria for the assessment of the adequacy of tests generated during integration testing. We present a mutation based interprocedural criterion, named Interface Mutation (IM), suitable for use during integration testing. A case study to evaluate the proposed criterion is reported. In the study, the UNIX sort utility was seeded with errors and Interface Mutation evaluated by measuring the cost of its application and its error revealing effectiveness. Alternative IM criteria using different sets of Interface Mutation operators were also evaluated. While comparing the error revealing effectiveness of these Interface Mutation-based test sets with same size randomly generated test sets, we observed that in most cases Interface Mutation based test sets are superior. The results suggest that Interface Mutation offers a viable test adequacy criteria for use at the integration level.