code-refactor

mhattingpete's avatarfrom mhattingpete

Perform bulk code refactoring operations like renaming variables/functions across files, replacing patterns, and updating API calls. Use when users request renaming identifiers, replacing deprecated code patterns, updating method calls, or making consistent changes across multiple locations.

⭐126stars🔀16forks📁View on GitHub🕐Updated Dec 19, 2025
[Code Generation]

When & Why to Use This Skill

The Code Refactor skill for Claude provides a powerful solution for systematic, multi-file code modifications. It specializes in bulk operations such as renaming variables, updating deprecated API calls, and pattern replacement. Designed for efficiency, it utilizes a specialized code-execution mode for large-scale tasks involving 10 or more files, offering up to 90% token savings compared to traditional editing methods. This tool ensures codebase consistency and accelerates technical debt reduction by automating repetitive structural changes with high precision.

Use Cases

  • 1. Global Identifier Renaming: Seamlessly update variable, function, or class names across dozens of files while ensuring all references are consistently modified.
  • 2. API and Library Migrations: Efficiently replace deprecated patterns or update method signatures to align with new API versions or internal standards across the entire repository.
  • 3. Legacy Code Modernization: Automate the conversion of outdated syntax (e.g., switching from 'var' to 'let/const') or legacy patterns to modern coding standards.
  • 4. Bulk Pattern Replacement: Apply consistent changes to repetitive code structures, configuration strings, or boilerplate code across multiple modules simultaneously.
namecode-refactor
descriptionPerform bulk code refactoring operations like renaming variables/functions across files, replacing patterns, and updating API calls. Use when users request renaming identifiers, replacing deprecated code patterns, updating method calls, or making consistent changes across multiple locations.

Code Refactor

Systematic code refactoring across files. Auto-switches to execution mode for 10+ files (90% token savings).

Mode Selection

  • 1-9 files: Use native tools (Grep + Edit with replace_all)
  • 10+ files: Automatically use code-execution skill

Execution example (50 files):

from api.code_transform import rename_identifier
result = rename_identifier('.', 'oldName', 'newName', '**/*.py')
# Returns: {'files_modified': 50, 'total_replacements': 247}
# ~500 tokens vs ~25,000 tokens traditional

When to Use

  • "rename [identifier] to [new_name]"
  • "replace all [pattern] with [replacement]"
  • "refactor to use [new_pattern]"
  • "update all calls to [function/API]"
  • "convert [old_pattern] to [new_pattern]"

Core Workflow (Native Mode)

1. Find All Occurrences

Grep(pattern="getUserData", output_mode="files_with_matches")     # Find files
Grep(pattern="getUserData", output_mode="content", -n=true, -B=2, -A=2)  # Verify with context

2. Replace All Instances

Edit(
  file_path="src/api.js",
  old_string="getUserData",
  new_string="fetchUserData",
  replace_all=true
)

3. Verify Changes

Grep(pattern="getUserData", output_mode="files_with_matches")  # Should return none

Workflow Examples

Rename Function

  1. Find: Grep(pattern="getUserData", output_mode="files_with_matches")
  2. Count: "Found 15 occurrences in 5 files"
  3. Replace in each file with replace_all=true
  4. Verify: Re-run Grep
  5. Suggest: Run tests

Replace Deprecated Pattern

  1. Find: Grep(pattern="\\bvar\\s+\\w+", output_mode="content", -n=true)
  2. Analyze: Check if reassigned (let) or constant (const)
  3. Replace: Edit(old_string="var count = 0", new_string="let count = 0")
  4. Verify: npm run lint

Update API Calls

  1. Find: Grep(pattern="/api/auth/login", output_mode="content", -n=true)
  2. Replace: Edit(old_string="'/api/auth/login'", new_string="'/api/v2/authentication/login'", replace_all=true)
  3. Test: Recommend integration tests

Best Practices

Planning:

  • Find all instances first
  • Review context of each match
  • Inform user of scope
  • Consider edge cases (strings, comments)

Safe Process:

  1. Search → Find all
  2. Analyze → Verify appropriate
  3. Inform → Tell user scope
  4. Execute → Make changes
  5. Verify → Confirm applied
  6. Test → Suggest running tests

Edge Cases:

  • Strings/comments: Ask if should update
  • Exported APIs: Warn of breaking changes
  • Case sensitivity: Be explicit

Tool Reference

Edit with replace_all:

  • replace_all=true: Replace all occurrences
  • replace_all=false: Replace only first (or fail if multiple)
  • Must match EXACTLY (whitespace, quotes)

Grep patterns:

  • -n=true: Show line numbers
  • -B=N, -A=N: Context lines
  • -i=true: Case-insensitive
  • type="py": Filter by file type

Integration

  • test-fixing: Fix broken tests after refactoring
  • code-transfer: Move refactored code
  • feature-planning: Plan large refactorings