Worked on the YSTEMandChess/react repository to enhance the reliability of the Chess module by expanding automated testing for the Lessons and Puzzles components. Focused on increasing test coverage for core gameplay flows, including socket connections and drag-and-drop interactions, to ensure correctness across multiple game scenarios. Utilized React for front end development and implemented tests using JavaScript and TypeScript, with structured data managed in JSON. This effort improved continuous integration confidence and established a foundation for safer future refactoring. The work prioritized robustness and maintainability, enabling faster feature delivery while reducing the risk of regressions in critical gameplay features.