Constraint Solving for Generating Glass-Box Test Cases

Glass-box testing tries to cover paths through the tested code, based on a given criterion such as def-use chain coverage. When generating glass-box test cases manually, the user is likely to overlook some def-use chains. Moreover it is difficult to find suitable test cases which cause certain def-use chains to be passed. We have developed a tool which automatically generates a system of test cases for a piece of Java byte code, which ensures that all def-use chains are covered. The tool consists of a symbolic Java virtual machine (SJVM) and a system of dedicated constraint solvers. The SJVM uses the constraint solvers in order to determine which branches the symbolic execution needs to consider. A backtracking mechanism is applied in case that several branches remain feasible. Thus we have applied implementation techniques known from functional logic and constraint programming to handle the considered applications problems.