Refactoring Patterns Skill
Safe transformations — same behavior, better structure.
Golden Rule
Tests pass before AND after.
When to Refactor
| Trigger | Action |
|---|---|
| Feature is hard to add | Refactor first |
| Same bug twice | Refactor to prevent |
| "I don't understand" | Refactor for clarity |
When NOT to Refactor
- •No tests + time pressure
- •Code won't change
- •Right before release
- •Should rewrite instead
Core Moves
| Move | When |
|---|---|
| Extract Function | Does too many things |
| Inline Function | Body clear as name |
| Extract Variable | Complex expression |
| Rename | Name doesn't reveal intent |
| Move Function | Uses other class's data |
Code Smells → Fix
| Smell | Refactoring |
|---|---|
| Long function | Extract Function |
| Long param list | Parameter Object |
| Duplicate code | Extract Function |
| Feature envy | Move Function |
| Large class | Extract Class |
Refactor vs Rewrite
| Refactor | Rewrite |
|---|---|
| Core logic sound | Design is wrong |
| Tests exist | Untestable |
| <30% changes | >70% changes |
Safe Workflow
Commit → Test → Small change → Test → Commit → Repeat
Synapses
See synapses.json for connections.