Worked on the supabase/supabase-js repository to enhance the reliability of endpoint construction by addressing a bug in SupabaseClient’s URL normalization. Focused on improving how custom base URLs with sub-paths are handled, replacing the previous stripTrailingSlash method with ensureTrailingSlash to standardize URL formatting. This change ensures that sub-paths are preserved, reducing errors for customers using non-root URLs and streamlining the developer experience. Utilized JavaScript and TypeScript, applying skills in API integration, full stack development, and testing to deliver a robust solution that minimizes edge-case failures and improves the consistency of service endpoint generation across different deployment scenarios.