An Automated Approach to Inheritance and Polymorphic Testing using a VDM++ Specification

The use of formal methods is growing with the rapidly increasing applications of safety-critical systems in such fields as aviation, medicine, railways etc. The benefits of using formal methods are not limited to avoidance of specification errors and elimination of ambiguities only - a formal specification also provides a sound basis for generating test suites. However, most of the work in this area has focused on unit testing only. In object-oriented paradigm, inheritance and polymorphism are powerful features, yet they present new challenges to the testers. In this paper, the authors present a novel approach to automated generation of test cases from a VDM++ specification. The authors base the testing technique on Offutt et al.'s fault model for subtype inheritance and polymorphic testing.