Dynamic Unit Test Extraction Via Time Travel Debugging for Test Cost Reduction

Compared to system tests, unit tests execute faster and allow more precise fault localisation. Hence, it can be beneficial to automatically extract unit tests and displace associated system tests. However, the extraction process may encounter challenges such as the identification of relevant test objectives, scalability issues, and future maintainability of serialized state. % To address these challenges, we exploit time travel debugging for efficient and accurate reconstruction of object states and use differential analysis of code coverage data. This allows us to extract code-only unit tests with a feasible overhead. The extracted unit tests mimic relevant parts of the system tests and, by displacing the latter in early testing stages, save resources. Our preliminary evaluation indicates large potentials for test cost reduction and high practical acceptance.