skills.rest
kazuph
kazuphCOMMUNITY
Explore all skills by this author →
GitHub

improve-legacy-code

Guide phased refactoring of legacy code with version control, tests, and Clean Architecture.

Updated Aug 23, 2026
Search Tags:#testing#tdd#refactoring#clean architecture#legacy code#domain model
One-click install
npx skills add https://github.com/kazuph/dotfiles --skill improve-legacy-code
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: improve-legacy-code
Source: https://github.com/kazuph/dotfiles/tree/main/claude/skills/improve-legacy-code
Command: npx skills add https://github.com/kazuph/dotfiles --skill improve-legacy-code

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill guides users through the process of safely refactoring and improving legacy codebases that lack tests and proper structure, making them more maintainable and robust.

Core Features & Use Cases

  • Phased Refactoring: Follows a structured approach from version control to Clean Architecture.
  • Test Introduction: Emphasizes creating automated tests before making changes.
  • TDD Guidance: Supports feature addition using the Test-Driven Development cycle.
  • Domain Model Extraction: Helps in separating core business logic from framework dependencies.
  • Use Case: A developer has a critical piece of old code with no tests. This Skill will guide them to add version control, write a basic test, and then refactor the code safely.

Quick Start

Guide me through the first step of preparing legacy code for refactoring by ensuring it is under version control.

Frequently Asked Questions about improve-legacy-code

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I safely refactor legacy code that has no tests?▼

Safely refactoring legacy code requires starting with version control, then introducing automated tests to lock in current behavior before making any structural changes or decoupling logic from framework dependencies.

What is the best way to add tests to old code before refactoring?▼

The best way to add tests before refactoring is to follow a structured methodology that introduces automated tests first, allowing you to verify existing behavior before attempting domain model extraction or architectural improvements.

How does TDD help when improving a legacy codebase?▼

TDD helps improve a legacy codebase by supporting feature addition through a structured test-driven cycle, ensuring new code is covered by tests and safely integrated without breaking existing untested logic.

Can I extract a domain model from code tightly coupled to a framework?▼

Yes, you can extract a domain model by carefully separating core business logic from framework dependencies. This architectural improvement decouples the logic, making the legacy codebase more maintainable and robust.

What are the phases of refactoring a legacy codebase?▼

The phases of refactoring a legacy codebase include setting up version control, introducing automated tests, applying Test-Driven Development, extracting the domain model, and implementing architectural improvements like Clean Architecture.

When should I not use Clean Architecture on legacy code?▼

You should avoid implementing Clean Architecture on legacy code if you cannot first establish automated tests, as safely decoupling business logic from frameworks requires a safety net to prevent breaking existing behavior during the transition.

Related Skills

Explore More Software Engineering Skills→
ThalfmanThalfman

git-guardrails-claude-code

Configure git hooks to block destructive commands in Claude Code repositories.

Community
Intermediate
IJHackIJHack
1.1k

qtpass-testing

Execute QtPass unit and integration tests and generate coverage reports.

Official
Intermediate
wildwasserwildwasser
35

test-driven-development

Enforce test-first development with failing tests before minimal code.

Community
Intermediate
laurentvvlaurentvv

Utilisation directe des Tools Python pour accélération

Execute Oil-Agent Python tools directly to bypass the smolagents cycle.

Community
Intermediate