refactor

name	refactor
description	Clean up code without changing behavior. Use when the user says code is messy, hard to read, too complex, wants to simplify, reduce duplication, or prepare code for a new feature.
user-invocable	true

Refactor

Clean up code. Make it simpler, clearer, or more maintainable without changing what it does.

When to refactor

• You're about to add a feature and the existing code makes it hard
• You see the same logic in three or more places
• A function is longer than 40 lines
• You need to read a function twice to understand it
• Nesting is deeper than 3 levels

When NOT to refactor

• Code you're not otherwise touching. Stay focused on the task at hand.
• Code that works and nobody needs to change. Leave it alone.
• Right before a deadline. Refactoring is for when you have room to verify.

Techniques

• Extract function: repeated code becomes a named function
• Early return: replace nested if/else with guard clauses
• Rename: if the name doesn't explain the purpose, change it
• Inline: if a function is called once and adds no clarity, inline it
• Split file: if a file has two unrelated responsibilities, split it

Process

1. Make sure tests pass before you start
2. Make one small change at a time
3. Run tests after each change
4. Commit when tests pass
5. Repeat

Rules

• Never refactor and change behavior in the same commit. Refactoring means the tests still pass with no changes to the tests.
• Don't abstract prematurely. Three concrete examples before you extract a pattern.
• Simpler is better. If your refactor adds more code than it removes, reconsider.