copilot-tdd-harness: Skill for Claude Code

.github/skills/tdd-refactor/SKILL.md

tdd-refactor is a skill for Claude Code from mrlarson2007/copilot-tdd-harness. It costs 31 tokens per session (385 once invoked), scanned A, original, MIT.

A workflow for improving code and tests after they pass, while keeping the software's existing behaviour unchanged. TDD means test-driven development: writing tests around expected behaviour as part of development.

In plain words
What is it for?
Use it to refactor a completed change, introduce helpers or builders when useful, and record evidence that the tests still pass.
Why use it?
It helps make code easier to read and tests easier to extend without changing what the software does.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

This is mrlarson2007/copilot-tdd-harness's own configuration. It tells Claude Code how to work on copilot-tdd-harness itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything copilot-tdd-harness configures →

Reuse

Borrowing it

Nothing to install: this file belongs to mrlarson2007/copilot-tdd-harness. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/mrlarson2007/copilot-tdd-harness/master/.github/skills/tdd-refactor/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/mrlarson2007/copilot-tdd-harness

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for tdd-refactor

README.md
[![agentmods](https://agentmods.dev/badge/skills/mrlarson2007/copilot-tdd-harness/tdd-refactor.svg)](https://agentmods.dev/skills/mrlarson2007/copilot-tdd-harness/tdd-refactor)
Your own site
<a href="https://agentmods.dev/skills/mrlarson2007/copilot-tdd-harness/tdd-refactor"><img src="https://agentmods.dev/badge/skills/mrlarson2007/copilot-tdd-harness/tdd-refactor.svg" alt="Measured on agentmods" height="20"></a>
Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 385 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00031 $0.00385
Opus 5 $0.00015 $0.00192
Sonnet 5 $0.00006 $0.00077
Haiku 4.5 $0.00003 $0.00038

Measured 7d ago against content hash 5635a42e07bc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

tdd-refactor scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.github/skills/tdd-refactor/SKILL.md · 47 lines

What it actually says

TDD Refactor Phase Skill

Purpose

  • Improve code and test design after green
  • Preserve all existing behavior
  • Prioritize readability over forced deduplication
  • Introduce helpers/builders when they improve future test authoring

Inputs

  • Commit details from commit stage (sha/message)
  • Committed baseline
  • Readability goals
  • Project refactor patterns from .github/instructions/tdd-patterns.instructions.md
  • Canonical REFACTOR style guide placeholder at .github/skills/tdd-refactor/assets/project-refactor-patterns.md

Outputs

  • Refactor diff
  • Test pass evidence
  • Helper/builder notes

Steps

  1. Load .github/skills/tdd-refactor/assets/project-refactor-patterns.md first, then load core asset files for refactor patterns, anti-patterns, and test readability
  2. Inspect surrounding code around each in-scope change before refactoring
  3. Refactor code and tests as needed
  4. Use tdd-test-run with a test_run_request contract whose expected result is a passing validation for the touched slice, then the broader suite required by project policy
  5. If the observed result does not match the expected REFACTOR outcome, revert only the scoped refactor changes and return to the pre-refactor baseline
  6. Return contract output

Completion Checks

  • All behavior preserved
  • Code and tests are more readable/maintainable
  • Helpers/builders introduced only when justified
Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 47 lines · 31 tokens per session scan A 5635a42e07bc

Subscribe to this mod's changes

tdd-refactor is a skill published in the GitHub repository mrlarson2007/copilot-tdd-harness (5 stars, last pushed 3mo ago), licensed MIT. It adds 31 tokens to every session and 385 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.