characterization-test-generator

Name: characterization-test-generator
Availability: InStock
Author: gustavscirulis

Generate characterization tests capturing current behavior of Swift code before refactoring.

114|8|Updated Mar 4, 2025

Search Tags:#testing #refactoring #regression testing #legacy code #characterization tests #AI assisted

Ready to run

npx skills add https://github.com/gustavscirulis/snapgrid --skill characterization-test-generator-gustavscirulis

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: characterization-test-generator
Source: https://github.com/gustavscirulis/snapgrid/tree/main/.claude/skills/skills/testing/characterization-test-generator
Command: npx skills add https://github.com/gustavscirulis/snapgrid --skill characterization-test-generator-gustavscirulis

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill generates characterization tests to capture the current behavior of existing code, providing a safety net before AI-assisted refactoring or modifications to legacy code.

Core Features & Use Cases

Behavior Capture: Documents what code actually does, not what it should do.
Refactoring Confidence: Enables safe modification of code by freezing current behavior as a regression suite.
Use Case: Before using an AI to refactor a critical, untested module, generate characterization tests to ensure no existing functionality is inadvertently broken.

Quick Start

Use the characterization-test-generator skill to generate tests for the ItemManager class.

Frequently Asked Questions about characterization-test-generator

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

FAQPage Schema

How do I safely refactor legacy Swift code that has no existing tests?▼

To safely refactor legacy code, generate characterization tests that document what the code actually does. This captures current behavior as a regression suite, providing a safety net before AI-assisted modifications or refactoring untested modules.

What is a characterization test and when do I need it for refactoring?▼

A characterization test documents what code actually does, not what it should do. You need it before refactoring legacy or untested code to freeze current behavior as a regression suite, preventing unintended functional changes during AI-assisted modifications.

How do I generate a regression suite for Swift code before modifying it?▼

Use a characterization test generator to identify the public API surface, input/output types, side effects, dependencies, and state mutations of your Swift code. This process captures actual behavior to create a regression suite for safe modifications.

Can I use AI-assisted refactoring on untested modules without breaking functionality?▼

Yes, by generating characterization tests first to capture the actual behavior of the untested module. This creates a regression suite that verifies AI-assisted refactoring does not inadvertently break existing functionality.

Does the characterization test generator identify state mutations and side effects in Swift?▼

Yes, the generator identifies the public API surface, input/output types, side effects, dependencies, and state mutations for Swift code to accurately document current behavior before refactoring.