EXSYST: Search-based GUI testing

Test generation tools commonly aim to cover structural artefacts of software, such as either the source code or the user interface. However, focusing only on source code can lead to unrealistic or irrelevant test cases, while only exploring a user interface often misses much of the underlying program behavior. Our EXSYST prototype takes a new approach by exploring user interfaces while aiming to maximize code coverage, thus combining the best of both worlds. Experiments show that such an approach can achieve high code coverage matching and exceeding the code coverage of traditional unit-based test generators; yet, by construction every test case is realistic and relevant, and every detected failure can be shown to be caused by a real sequence of input events.