test-driven-development SKILL.md skillA
test-driven-development from jjuraszek/pi-gauntlet is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add jjuraszek/pi-gauntlet/test-driven-development@git:20261020.c79e361Pins git:20261020.c79e361 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- jjuraszek/pi-gauntlet
- Path
skills/test-driven-development/SKILL.md- Versions recorded
- 8
- Latest version
- git:20261020.c79e361, committed Oct 20, 2026
- First version recorded
- Aug 21, 2026
- Size
- 10,929 bytes
- Repository stars
- 19
- License
- a license file GitHub does not identify
Use when implementing any feature or bugfix, before writing implementation code.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
> **Related skills:** Before claiming done, use `/skill:verification-before-completion` to verify tests actually pass.
# Test-Driven Development (TDD)
## Overview
Write the test first. Watch it fail. Write minimal code to pass.
**Core principle:** If you didn't watch the test fail, you don't know if it tests the right thing.
**Violating the letter of the rules is violating the spirit of the rules.**
## Prerequisites
- Active worktree (not the primary checkout on `main`) — see `/skill:using-git-worktrees`
- Approved plan or clear task scope
Before starting implementation, call `phase_tracker({ action: "start", phase: "implement" })`.
## When to Use
**Always:**
- New features
- Bug fixes
- Refactoring
- Behavior changes
**Exceptions (ask your human partner):**
- Throwaway prototypes
- Generated code
- Configuration files
Thinking "skip TDD just this once"? Stop. That's rationalization.
If a tool result contains a ⚠️ workflow warning about TDD, stop immediately and write the failing test before continuing. The warning is not a checkbox to dismiss — it's the gate.
## The Iron Law
```
NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST
```
…Read the whole file at its exact version.
How to install
mdr add jjuraszek/pi-gauntlet/test-driven-development@sha256:e9b9b50bbbe2269aThe line at the top of this page pins the label git:20261020.c79e361, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_bse3fbx7qmeu6dxv)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 8 versions of this file, between Aug 21, 2026 and Oct 20, 2026, about one every 9 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261020.c79e361 latest | 2026-10-20 | c79e361 | 10,929 B | A | view · diff |
| git:20261017.836bbce | 2026-10-17 | 836bbce | 10,755 B | A | view · diff |
| git:20261007.4f2845d | 2026-10-07 | 4f2845d | 10,475 B | A | view · diff |
| git:20260923.c5481c1 | 2026-09-23 | c5481c1 | 8,366 B | A | view · diff |
| git:20260923.88370ec | 2026-09-23 | 88370ec | 8,143 B | A | view · diff |
| git:20260910.be2f85e | 2026-09-10 | be2f85e | 7,988 B | A | view · diff |
| git:20260906.0b47b93 | 2026-09-06 | 0b47b93 | 7,982 B | A | view · diff |
| git:20260821.2f7f763 | 2026-08-21 | 2f7f763 | 7,743 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (10929 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
jjuraszek/pi-gauntlet · 19 stars · license a license file GitHub does not identify · pushed 2026-10-20 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_bse3fbx7qmeu6dxv GET https://markdownregistry.com/api/v1/resolve?ref=jjuraszek/pi-gauntlet/test-driven-development GET https://markdownregistry.com/api/v1/blob/e9b9b50bbbe2269af25bbd4f9a47db2aa0e2b1cd357349753577f241b5c0ce60
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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