Refactor

Refactor: $ARGUMENTS

Safely refactor code while ensuring tests continue to pass.

Process

1. Understand Current State

• Read the target file(s)
• Identify existing tests
• Run tests to confirm they pass before changes:

  npm test -- --testPathPattern="[target]"
  

2. Plan Refactoring

Common refactoring types:

• Extract: Pull code into separate function/component
• Rename: Change names for clarity
• Simplify: Reduce complexity, remove duplication
• Restructure: Change file/folder organization

Document what will change and why.

3. Apply Changes Incrementally

Make small, focused changes:

1. One logical change at a time
2. Run tests after each change
3. If tests fail, fix immediately before continuing

4. Update Tests if Needed

If refactoring changes the API:

• Update test imports
• Update test assertions
• Add tests for new extracted functions

5. Validate

npm run build
npm run lint
npm test

6. Report Changes

Summarize:

• Files modified
• What was refactored and why
• Any API changes
• Test status

Refactoring Patterns

Extract Component:

// Before: Large component with embedded logic
// After: Smaller component + extracted sub-component

Extract Hook:

// Before: useState + useEffect logic in component
// After: Custom hook encapsulating the logic

Extract Utility:

// Before: Inline data transformation
// After: Pure function in lib/utils.ts

Safety Rules

• Never change behavior, only structure
• Tests must pass before AND after
• If unsure, add tests first
• Preserve public API unless explicitly requested