jds-refactor

Refactor code with characterization tests and atomic behavioral verification.

13|Updated Mar 24, 2026

Search Tags:#design #architecture #refactor #code-quality #software-engineering #tests #behavior-preserving

Ready to run

npx skills add https://github.com/josipmusa/jds --skill jds-refactor

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: jds-refactor
Source: https://github.com/josipmusa/jds/tree/main/skills/jds-refactor
Command: npx skills add https://github.com/josipmusa/jds --skill jds-refactor

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Refactoring to restructure code without changing external behavior, ensuring a safety net via tests and characterization.

Core Features & Use Cases

Behavior-preserving refactoring: rename, extract methods, move classes, and simplify logic.
Test-driven safety: write characterization tests if none exist and verify behavior after each atomic change.
Controlled workflow: plan, execute, verify, and clean up in small, verifiable steps.

Quick Start

Identify a refactoring target, ensure behavioral tests exist, then apply one atomic change at a time and verify tests after each step.

Frequently Asked Questions about jds-refactor

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

FAQPage Schema

How do I refactor code safely when there are no existing tests?▼

To refactor code safely without tests, generate characterization tests first to capture current behavior, then apply atomic changes and run tests after each step to verify behavioral equivalence.

What is behavior-preserving refactoring and when should I use it?▼

Behavior-preserving refactoring restructures code like renaming or extracting methods without altering externally observable behavior, and is used when debugging reveals structural issues or code quality needs improvement.

Can I move classes and extract methods without changing software behavior?▼

Yes, you can move classes and extract methods without changing software behavior by making atomic changes, verifying tests after each step, and ensuring the overall externally observable behavior remains equivalent.

What is the best way to reduce code duplication while maintaining functionality?▼

The best way to reduce code duplication while maintaining functionality is to plan controlled refactoring steps, write characterization tests if missing, and execute one atomic change at a time with test verification.

Why do I need characterization tests before restructuring my code architecture?▼

Characterization tests are needed before restructuring code architecture because they document existing behavior, providing a safety net to verify that each atomic refactoring step preserves the original externally observable functionality.