Worked on the City-of-Helsinki/yjdh repository to enhance the reliability of the application resubmission flow by developing comprehensive unit tests for the setIsResubmission logic. Focused on both draft and non-draft application scenarios, the approach included mocking dependencies such as API calls and routing to ensure tests remained isolated and robust. Using React and TypeScript, the developer ensured that edge cases were covered, including optional prop handling to prevent errors during submission. The resulting test suite improved maintainability and provided clear documentation, supporting future contributors and reducing the risk of production failures related to resubmission handling in the front end.