Worked on the firebase/firebase-js-sdk repository to enhance authentication reliability by achieving complete unit test coverage for Facebook, GitHub, and SAML authentication providers. Focused on expanding test suites to validate provider generation and error handling, ensuring robust initialization and consistent error management across all three providers. Employed TypeScript and JavaScript alongside Jest-based unit testing to systematically reduce production risk and improve maintainability. Although no user-facing features were introduced during this period, the work strengthened the quality assurance process for authentication flows, supporting safer and faster releases while increasing the overall reliability of authentication provider integrations within the codebase.