test-driven-development SKILL.md skillA

This file is byte-identical to the first copy the registry indexed, one of 3 indexed copies. Same content hash, so the same checks give both the same grade.

test-driven-development from takaakit/superpowers-uml is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

mdr add takaakit/superpowers-uml/test-driven-development@git:20260804.eab20be

Pins git:20260804.eab20be in mdr.lock. Pin the fingerprint instead.

Audit grade

A, 17 of 17 checks passed

Kind

SKILL.md skill

Repository

takaakit/superpowers-uml

Path

plugins/superpowers-uml/skills/test-driven-development/SKILL.md

Versions recorded

2

Latest version

git:20260804.eab20be, committed Aug 4, 2026

First version recorded

Apr 3, 2026

Size

9,015 bytes

Repository stars

12

License

none declared

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

# 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.**

## 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.

## The Iron Law

```
NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST
```

Write code before the test? Delete it. Start over.

**No exceptions:**
- Don't keep it as "reference"
- Don't "adapt" it while writing tests
- Don't look at it
- Delete means delete

Implement fresh from tests. Period.

## Red-Green-Refactor

```dot
digraph tdd_cycle {
    rankdir=LR;
    red [label="RED\nWrite failing test", shape=box, style=filled, fillcolor="#ffcccc"];
    verify_red [label="Verify fails\ncorrectly", shape=diamond];
    green [label="GREEN\nMinimal code", shape=box, style=filled, fillcolor="#ccffcc"];
…

Read the whole file at its exact version.

How to install

mdr add takaakit/superpowers-uml/test-driven-development@sha256:bf1b8216e523851a

[![mdr](https://markdownregistry.com/badge/art_zwxgntam4th2u6nx.svg)](https://markdownregistry.com/a/art_zwxgntam4th2u6nx)

Versions

The registry has recorded 2 versions of this file, between Apr 3, 2026 and Aug 4, 2026, about one every 123 days.

Audit of the latest version

Source

API

GET https://markdownregistry.com/api/v1/artifacts/art_zwxgntam4th2u6nx
GET https://markdownregistry.com/api/v1/resolve?ref=takaakit/superpowers-uml/test-driven-development
GET https://markdownregistry.com/api/v1/blob/bf1b8216e523851a411e91d429a7c1c2a173e79d88957bc78e348218d50edd54

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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