How do I install the Refactoring skill?

Run npx skillmds@latest add kienbui1995/refactoring in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Refactoring safe to use?

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Which AI agents work with Refactoring?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Refactoring free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Refactoring?

kienbui1995 (@kienbui1995) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Refactoring by kienbui1995 — Agent Skill

Name: Refactoring
Author: kienbui1995

File contents

Code Refactoring

Overview

Refactoring improves code structure without changing external behavior. Every refactoring must be backed by passing tests.

Core principle: Small, safe, verified steps. Never refactor and add features simultaneously.

When to Use

Code smells: long methods, deep nesting, duplicated logic, unclear naming
Before adding features to messy code ("make the change easy, then make the easy change")
After getting tests green — clean up before committing
Tech debt reduction sprints

The Refactoring Loop

1. Ensure tests pass (green baseline)
2. Identify ONE smell
3. Apply ONE refactoring
4. Run tests → must stay green
5. Commit
6. Repeat

Common Refactorings by Smell

Smell	Refactoring
Long method (>20 lines)	Extract Method
Deep nesting (>3 levels)	Early return / Guard clauses
Duplicated code	Extract shared function/module
Primitive obsession	Introduce value object/type
Long parameter list (>3)	Introduce parameter object
Feature envy	Move method to owning class
God class	Extract class by responsibility
Magic numbers/strings	Extract named constants
Complex conditional	Extract to named boolean / strategy pattern
Shotgun surgery	Consolidate into single module

Safety Rules

Tests first — no tests = no refactoring. Write characterization tests if none exist.
One refactoring per commit — easy to revert if something breaks
No behavior changes — if you're changing what code does, that's not refactoring
Run tests after every step — not just at the end
Use IDE tools — rename, extract, inline are safer automated

Red Flags — STOP

Signal	Action
Tests failing after refactoring	Revert immediately, smaller step
Refactoring + feature in same commit	Split into two commits
"While I'm here, let me also..."	Finish current refactoring first
No tests exist	Write characterization tests before touching code

Integration

magic-powers:test-driven-development — ensure test coverage before refactoring
magic-powers:verification-before-completion — verify behavior unchanged after refactoring
magic-powers:requesting-code-review — get review on significant refactors

---name: refactoringdescription: Use when improving code structure without changing behavior - extract methods, simplify conditionals, reduce duplication, improve naming---# Code Refactoring## OverviewRefactoring improves code structure without changing external behavior. Every refactoring must be backed by passing tests.**Core principle:** Small, safe, verified steps. Never refactor and add features simultaneously.## When to Use- Code smells: long methods, deep nesting, duplicated logic, unclear naming- Before adding features to messy code ("make the change easy, then make the easy change")- After getting tests green — clean up before committing- Tech debt reduction sprints## The Refactoring Loop```1. Ensure tests pass (green baseline)2. Identify ONE smell3. Apply ONE refactoring4. Run tests → must stay green5. Commit6. Repeat```## Common Refactorings by Smell| Smell | Refactoring ||-------|-------------|| Long method (>20 lines) | Extract Method || Deep nesting (>3 levels) | Early return / Guard clauses || Duplicated code | Extract shared function/module || Primitive obsession | Introduce value object/type || Long parameter list (>3) | Introduce parameter object || Feature envy | Move method to owning class || God class | Extract class by responsibility || Magic numbers/strings | Extract named constants || Complex conditional | Extract to named boolean / strategy pattern || Shotgun surgery | Consolidate into single module |## Safety Rules1. **Tests first** — no tests = no refactoring. Write characterization tests if none exist.2. **One refactoring per commit** — easy to revert if something breaks3. **No behavior changes** — if you're changing what code does, that's not refactoring4. **Run tests after every step** — not just at the end5. **Use IDE tools** — rename, extract, inline are safer automated## Red Flags — STOP| Signal | Action ||--------|--------|| Tests failing after refactoring | Revert immediately, smaller step || Refactoring + feature in same commit | Split into two commits || "While I'm here, let me also..." | Finish current refactoring first || No tests exist | Write characterization tests before touching code |## Integration- **magic-powers:test-driven-development** — ensure test coverage before refactoring- **magic-powers:verification-before-completion** — verify behavior unchanged after refactoring- **magic-powers:requesting-code-review** — get review on significant refactors

Frequently asked questions

Refactoring