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 working refactor is a commit
5. Don't mix refactoring with feature work: Separate concerns