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characterization-test-generator

Generate characterization tests that document current behavior before refactoring.

Updated Mar 1, 2026
Search Tags:#refactoring#regression#test-generation#tests#legacy-code#characterization#behavior-documentation
One-click install
npx skills add https://github.com/mazicimert/RunDom --skill characterization-test-generator-mazicimert
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: characterization-test-generator
Source: https://github.com/mazicimert/RunDom/tree/main/.claude/skills/testing/characterization-test-generator
Command: npx skills add https://github.com/mazicimert/RunDom --skill characterization-test-generator-mazicimert

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Characterization-test-generator creates tests that document what existing code actually does, preserving behavior as a regression safety net during refactoring of legacy code.

Core Features & Use Cases

  • Generate tests that lock current behavior for safe AI-assisted refactoring.
  • Identify public API surface, inputs, outputs, side effects, and dependencies to seed robust regression suites.
  • Use cases include evolving or migrating legacy modules, or ensuring changes do not alter observable behavior.

Quick Start

Identify the target module and run the generator to produce characterization tests that document current behavior before refactoring.

Frequently Asked Questions about characterization-test-generator

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

FAQPage Schema
How do I capture current behavior before refactoring legacy code?▼

To capture current behavior before refactoring, you generate characterization tests that document what existing code actually does, creating a regression safety net. This preserves observable behavior during code changes.

What are characterization tests and when do I need them for regression safety?▼

Characterization tests are regression tests that lock in the current behavior of existing code. You need them when evolving or migrating legacy modules to ensure changes do not alter observable behavior.

How do I generate tests that document public API surface and side effects?▼

To generate tests that document public API surface, inputs, outputs, and side effects, run the characterization generator on your target module. It outputs a structured test suite capturing actual behavior.

What's the best way to lock current behavior for safe AI-assisted refactoring?▼

The best way to lock current behavior for safe AI-assisted refactoring is generating characterization tests that document actual behavior. These tests identify dependencies and guard refactoring across modules.

Can I use characterization tests for migrating legacy modules across dependencies?▼

Yes, characterization tests are used for migrating legacy modules across dependencies. They identify input and output types, document side effects, and ensure changes do not alter observable behavior.

Why does refactoring legacy code require behavior documentation tests?▼

Refactoring legacy code requires behavior documentation tests because legacy systems often lack adequate test coverage. Characterization tests capture actual behavior, providing a regression safety net to guide safe code changes.

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