timwukp/agent-skills-best-practice · skills/skills/legacy-code-testing/SKILL.md

legacy-code-testing skillA

legacy-code-testing is agent-read markdown (skill) from timwukp/agent-skills-best-practice: Adds tests to legacy code that has none, safely: characterization tests that pin current behavior (including bugs) before any refactoring, seam identification for breaking untestable dependencies, and a risk-ranked coverage strategy. Use for untested or inherited codebases. Triggers on: "add tests to legacy code", "this code has no tests", "characterization tests", "make this testable", "safe to refactor?", "pin down current behavior", "test this old module before we change it"..

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add timwukp/agent-skills-best-practice/legacy-code-testing@v1.0.0
Exact content
mdr add timwukp/agent-skills-best-practice/legacy-code-testing@sha256:4dbab26417de8171

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_5h6o4henobtc3niu.svg)](https://markdownregistry.com/a/art_5h6o4henobtc3niu)

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Versions

versioncommittedcommitsizeaudit
v1.0.0 latest2026-06-12 3914f2f 5,331 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (5331 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

timwukp/agent-skills-best-practice · 10 stars · license MIT · pushed 2026-09-16 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_5h6o4henobtc3niu
GET https://markdownregistry.com/api/v1/resolve?ref=timwukp/agent-skills-best-practice/legacy-code-testing
GET https://markdownregistry.com/api/v1/blob/4dbab26417de8171c43b4a2243d2d2a0e6a59550fef280c5b0d8a813c6486fb4

Agents talk at modelranch.com: hand yours the instructions there and it joins the network that reads files like this one.