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
<!-- VENDORED from jeswr/prod-solid-server `.agents/skills/test-driven-development/`
(SKILL.md + testing-anti-patterns.md), unmodified. The upstream repository carries
no LICENSE file at vendor time; vendored by arrangement with the owner (@jeswr).
Mirrored here for sparq's certification framework (epic sq-toze, bead sq-toze.1) so
gap-fixes across the memsafety/sbom/cis/asvs worktrees land test-first. -->
# 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
…
The line at the top of this page pins the label git:20261005.afb6bad, 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.
A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the 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 (10277 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
sparq-org/sparq · 13 stars · license MIT · pushed 2026-10-29 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_54sya72u7joylphd
GET https://markdownregistry.com/api/v1/resolve?ref=sparq-org/sparq/test-driven-development
GET https://markdownregistry.com/api/v1/blob/532e41dc4bfdc253dc065fe043e2fd972c3fa9d782c13c0af930a1e10e073c5d
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.
sparq-org/sparq · .claude/skills/ast-grep/SKILL.md · Understand code STRUCTURE without reading whole files — outline a large file to its signatures, structural-grep every…
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sparq-org/sparq · .claude/skills/query-pkg/SKILL.md · Answer a "what does the repo say about X, where was Y decided, what is the status or provenance of Z, which sources are…
sparq-org/sparq · .claude/skills/rust-parallel-parsing/SKILL.md · How to make text-format parsing (N-Triples / Turtle / line-delimited records) go fast in Rust by chunk-parallel…
sparq-org/sparq · .claude/skills/sparql-formal-semantics/SKILL.md · Cheat-sheet for the formal semantics of the SPARQL fragment used in the ZKP-SPARQL paper — Pérez–Arenas–Gutiérrez…
addyosmani/agent-skills · skills/test-driven-development/SKILL.md · Drives development with tests using the red-green-refactor loop. Use when implementing any logic, fixing any bug, or…
mvschwarz/openrig · skills/_canonical/process/test-driven-development/SKILL.md · Use when implementing any feature or bugfix, before writing implementation code
mvschwarz/openrig · packages/daemon/specs/agents/shared/skills/process/test-driven-development/SKILL.md · Use when implementing any feature or bugfix, before writing implementation code
cbrock84/headcount · plugins/technology/skills/test-driven-development/SKILL.md · Drives implementation by writing a failing test first, then the smallest code that passes it. Use this before writing…
a5c-ai/babysitter · library/methodologies/superpowers/skills/test-driven-development/SKILL.md · Use when implementing any feature or bugfix, before writing implementation code. Enforces RED-GREEN-REFACTOR cycle.
a5c-ai/babysitter · library/methodologies/rpikit/skills/test-driven-development/SKILL.md · Test-first development practice where test specifications are written before production code, integrated into plan…
