During their work on the kuzudb/kuzu repository, Xu enhanced the robustness of end-to-end testing by developing and integrating a refined FSM Leak Checker. They introduced a SKIP_FSM_LEAK_CHECK token, allowing selective bypass of leak checks in specific tests, and refactored the FSMLeakChecker for improved reliability and maintainability. By embedding the leak checker directly into the test runner, Xu ensured comprehensive coverage across all applicable end-to-end tests, reducing flaky outcomes and accelerating feedback cycles. This work leveraged C++ and Python, drawing on expertise in CI/CD, database internals, and testing to deliver deeper test control and more stable release processes.