Developed a metadata validation testing feature for the open-feature/js-sdk-contrib repository, focusing on enhancing the reliability of feature flag management with Flagd. Leveraging TypeScript and end-to-end testing methodologies, the work introduced automated checks to validate flag metadata properties, ensuring correct behavior and reducing the risk of misconfiguration in production environments. The implementation strengthened the existing testing framework by adding targeted coverage for metadata scenarios, improving maintainability and laying the foundation for broader validation capabilities in the future. This contribution demonstrated a methodical approach to software testing, emphasizing robust validation and maintainable code within a TypeScript-based codebase.