Code Refactoring Patterns A comprehensive guide to refactoring code systematically while maintaining functionality and improving quality. When to Refactor - Code smells detected (duplicated code, long functions, etc.) - Before adding new features to complex areas - After understanding improves ("now I see a better way") - When tests are in place - Performance optimization needed Refactoring Rules 1. Never refactor without tests : Write tests first if they don't exist 2. Small steps : Make one change at a time 3. Run tests after each change : Ensure nothing breaks 4. Commit often : Each workin…