MUT4SLX: Extensions for Mutation Testing of Stateflow Models

Several experience reports illustrate that mutation testing is capable of supporting a “shift-left” testing strategy for software systems coded in textual programming languages like C++. For graphical modeling languages like Simulink, such experience reports are missing, primarily because of a lack of adequate tool support. In this paper, we extend MUT4SLX, a tool for automatic mutant generation and test execution of Simulink models based on block diagrams. The tool is extended to support mutation operators for Stateflow models, which, to the best of our knowledge, are not supported by any other tool. The current version of MUT4SLX has 8 operators that are modeled after realistic faults (mined from an industrial bug database) and are fast to inject (by only replacing the parameter values). An experimental evaluation on four sample projects shows that MUT4SLX is capable of performing mutation analysis reasonably fast, but mutant execution is always more time-consuming.