Test-Driven Development Overview Write a failing test before writing the code that makes it pass. For bug fixes, reproduce the bug with a test before attempting a fix. Tests are proof — "seems right" is not done. A codebase with good tests is an AI agent's superpower; a codebase without tests is a liability. When to Use - Implementing any new logic or behavior - Fixing any bug (the Prove-It Pattern) - Modifying existing functionality - Adding edge case handling - Any change that could break existing behavior When NOT to use: Pure configuration changes, documentation updates, or static content…