June 2025 summary for mongodb/mongo-go-driver: Implemented a targeted testability improvement in drivertest by introducing a named error ErrNoResponsesRemaining to replace an anonymous error. This change clarifies the failure mode when the mocked connection exhausts buffered responses, enabling downstream code and tests to explicitly detect and handle this condition. No major bug fixes were recorded for the month. Overall, the work enhances test reliability, speeds debugging, and supports more robust test instrumentation, contributing to higher confidence in CI outcomes and downstream consumer stability. Technologies showcased include Go, error handling patterns, and test doubles in the drivertest harness, with a concrete commit reference: e20ed462cdafad3b7dae85abb032fd9d962e904b.