When should I use the Legacy Code Safety skill?

You should activate this skill whenever you are tasked with modifying, refactoring, or deleting code that lacks comprehensive test coverage, especially in high-risk dynamic languages like Python or JavaScript.

How does the RGR workflow differ for legacy code?

In the legacy RGR workflow, 'Red' signifies writing a test that captures current reality (even if buggy), 'Green' verifies the test matches reality, and 'Refactor' is where the actual modification occurs under a safety net.

What is characterization testing?

Characterization testing is the process of writing tests that describe the current actual behavior of a piece of software. Unlike TDD, which tests for intended behavior, characterization tests ensure you understand what the code currently does before you try to change it.

What is the Strangler Fig pattern mentioned in the skill?

The Strangler Fig pattern is a risk-mitigation strategy where you wrap legacy code in a new, tested interface and gradually migrate functionality to the new implementation until the old code can be safely removed.

Legacy Code Safety

Name: Legacy Code Safety
Author: TheBushidoCollective

byTheBushidoCollective

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Seguridad y Pruebas

Implements a rigorous characterization testing workflow to safely modify, refactor, or remove untested legacy code.

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Legacy Code Safety provides a structured framework for Claude to handle high-risk modifications in codebases lacking test coverage. By enforcing the 'Golden Rule'—never modify untested code without adding tests first—this skill ensures that existing behaviors are documented through characterization tests before any logic is changed. It guides the user through the RGR (Red-Green-Refactor) workflow specifically tailored for legacy systems and offers advanced strategies like the Strangler Fig pattern to minimize regressions while managing technical debt in complex, production environments.

Características Principales

Incremental migration guidance via the Strangler Fig pattern
Characterization testing workflow to capture and verify existing behavior
39 GitHub stars
Tailored risk assessment for dynamic and statically-typed languages
Integration with code coverage and mutation testing diagnostics
Pre-modification safety checklists to prevent accidental regressions

Casos de Uso

Modernizing large-scale legacy modules using incremental replacement
Refactoring mission-critical functions that lack existing unit tests
Safely deleting deprecated code without breaking hidden dependencies

Acerca de

Características Principales

Incremental migration guidance via the Strangler Fig pattern
Characterization testing workflow to capture and verify existing behavior
39 GitHub stars
Tailored risk assessment for dynamic and statically-typed languages
Integration with code coverage and mutation testing diagnostics
Pre-modification safety checklists to prevent accidental regressions

Casos de Uso

Modernizing large-scale legacy modules using incremental replacement
Refactoring mission-critical functions that lack existing unit tests
Safely deleting deprecated code without breaking hidden dependencies