refactoring

name	refactoring
description	Patterns and strategies for safely refactoring code

Refactoring

Instructions

When the user asks you to refactor, clean up, or restructure code:

1. Understand first — read all related code before making changes
2. Preserve behavior — refactoring changes structure, not functionality
3. Small steps — make one change at a time, verify it works
4. Keep tests passing — if tests exist, run them after each change

Common Refactoring Patterns

Extract Function

Pull a block of code into its own function when:

• The block has a clear single purpose
• The same logic is duplicated elsewhere
• The containing function is too long (>30 lines)

Extract Module

Split a large file into separate modules when:

• Functions fall into distinct categories
• The file exceeds 200-300 lines
• Different parts have different dependencies

Replace Callbacks with Async/Await

• Convert callback-style APIs to promise-based
• Use util.promisify() for Node.js callback APIs
• Replace .then() chains with async/await

Simplify Conditionals

• Extract complex boolean expressions into named variables
• Use early returns to reduce nesting
• Replace if-else chains with lookup objects/maps

Remove Duplication

• Identify repeated code patterns
• Extract shared logic into a common function
• Use higher-order functions for similar-but-different operations

Safety Checklist

• All existing tests pass after each change
• No new functionality was added
• Exported API surface is unchanged
• No behavior changes (just structure)