Exploiting Annotations to Test Break-off Branches

Programs often contain branches to break off from their main execution. These branches contribute to the total cost of testing, because they also need to be tested. The paper presents a new approach to improve the testing of such branches by annotating them. Our tool automatically generates test-sequences. Then, invariants in the form of pre-and post-condition over the executions passing each annotated branch are dynamically inferred, and reported to the programmer for inspection. Contradiction with the programmer's assumption on what the behavior should be indicates a bug. As invariants, a certain class of simple expressions are proposed, which are discriminative enough for testing break-off behavior, while keeping their amount feasible for inspection.