Assertion-Based Validation of Modified Programs

Assertions are used to detect incorrect program behavior during testing and debugging. Assertions when combined with automated test data generation may increase the confidence that certain types of faults are not present in the program. If the test data generation process is not able to violate an assertion, a developer may have confidence that the fault "captured" by the assertion is not present. We refer to this process as an assertion-based validation. Assertion-based validation may be very expensive especially when a large number of assertions are present in a program. During maintenance, after a modification is made to the program, all unchanged assertions need to be revalidated to make sure that certain types of faults are present. In this paper we present an approach that may reduce the cost of assertion-based revalidation after modifications are made to the program by identifying assertions that need to be revalidated or only partially revalidated. The presented approach is based on program dependence analysis and testability transformation. The results of a small case study indicate that the presented approach may significantly reduce the effort during the process of assertion-based revalidation.