working-effectively-with-legacy-code

Apply Michael Feathers-inspired legacy-code rules when changing hard-to-test code safely with characterization tests, seams, sprout methods, or wrap methods.

Jump to install

Repository: ciembor/agent-rules-books
Last source activity: September 9, 2026 at 13:30
Detected SKILL.md language: English
Stars: 2,739
Forks: 486

Install options

The review-first prompt is selected by default. You can switch to a direct command or download a local copy.

Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.

A direct command skips the review prompt. Inspect the source before running it.

npx skills add https://github.com/ciembor/agent-rules-books --skill working-effectively-with-legacy-code

The command stays on one line. Scroll horizontally to inspect it before copying.

Prefer a local copy? Download the files currently available to SkillsMP.

Review the source files

Read SKILL.md and any companion files shown by SkillsMP before deciding whether to install.

File Explorer

4 files

SKILL.md

Source instructions · Read-only preview

name	working-effectively-with-legacy-code
description	Apply Michael Feathers-inspired legacy-code rules when changing hard-to-test code safely with characterization tests, seams, sprout methods, or wrap methods.
license	MIT