safe-refactor

When to Use

Perform safe refactoring when:

• Renaming functions, variables, or classes
• Restructuring code for better organization
• Optimizing performance-critical sections
• Improving code readability and maintainability
• Extracting methods or classes
• Consolidating duplicate code

Critical Patterns

Safety First Approach

ALWAYS follow this sequence:

1. Analyze - Understand current code and dependencies
2. Backup - Create git branch or stash current changes
3. Incremental Changes - Make small, verifiable changes
4. Rollback Ready - Know how to revert if issues occur

Code Analysis Requirements

Before refactoring:

• Use Grep to find all usages of the target code
• Use Read to understand current implementation
• Identify dependencies and side effects
• Check for complex logic that needs careful handling

Change Management

• Atomic Changes: Each refactoring should be a single, focused change
• Test After Each Step: Never batch changes without validation
• Documentation Updates: Update comments and docs as you refactor
• Interface Preservation: Maintain public APIs unless explicitly changing them

Refactoring Types

Function/Method Refactoring

// Before
function oldFunction(param1, param2) {
  // complex logic
}

// After (safe rename)
function newFunctionName(param1, param2) {
  // same complex logic
}

Variable Renaming

// Before
const usr = getUser();

// After
const user = getUser();

Code Extraction

// Extract method safely
function processData(data) {
  // Before: inline logic
  const result = data.map((item) => item.value * 2);
  return result.filter((val) => val > 10);
}

// After: extracted function
function calculateValues(data) {
  return data.map((item) => item.value * 2);
}

function filterHighValues(values) {
  return values.filter((val) => val > 10);
}

function processData(data) {
  const result = calculateValues(data);
  return filterHighValues(result);
}

Validation Commands

Pre-Refactor Checks

# Run tests before starting
pnpm test

# Check linting
pnpm run lint

# Type checking
pnpm run typecheck

Post-Refactor Validation

# Run all validation steps
pnpm test && pnpm run lint && pnpm run typecheck

# Check for breaking changes
git diff --name-only

Rollback Procedures

Git-Based Rollback

# If on feature branch
git reset --hard HEAD~1  # Undo last commit
git checkout main        # Switch back
git branch -D feature-branch

# If working directory changes
git stash                # Save changes
# ... test rollback ...
git stash pop            # Restore if safe

Manual Rollback

• Keep original files backed up
• Have git history to reference
• Know which files were changed
• Test rollback thoroughly

Error Handling

Common Issues

Tests Failing After Refactor:

• Check if function signatures changed
• Verify all call sites updated
• Look for missing dependencies

Linting Errors:

• Fix import statements
• Update variable references
• Check for unused code

Type Errors:

• Update type definitions
• Fix interface changes
• Verify generic type usage

Recovery Steps

1. Stop and Assess: Don't make more changes
2. Revert Changes: Use git to undo problematic changes
3. Test Revert: Ensure rollback works
4. Retry Smaller: Break down into smaller changes
5. Get Help: Ask for code review if stuck

Best Practices

• Start Small: Refactor one function at a time
• Use IDE Tools: Leverage rename refactoring features
• Commit Often: Each successful change gets committed
• Document Changes: Update comments and READMEs
• Peer Review: Have someone verify complex refactors
• Measure Impact: Ensure performance doesn't degrade

Integration with Tools

With Git-Master Skill

Use git-master for version control operations:

• Creating feature branches
• Committing atomic changes
• Managing merge conflicts

With Testing Frameworks

Coordinate with testing tools:

• Run unit tests for affected code
• Update integration tests
• Add regression tests for complex changes

This skill ensures refactoring is performed safely with minimal risk of introducing bugs or breaking functionality.