tdd SKILL.md skillA

tdd from saifallah-star/aegis is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add saifallah-star/aegis/tdd@git:20261016.0f9b29d

Pins git:20261016.0f9b29d in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: saifallah-star/aegis
Path: .agents/skills/tdd/SKILL.md
Versions recorded: 1
Latest version: git:20261016.0f9b29d, committed Oct 16, 2026
Size: 3,738 bytes
Repository stars: 1
License: MIT

Test-driven development following a strict red-green-refactor loop across vertical slices. Use when writing code test-first, implementing new features with unit/integration tests, or fixing bugs test-first.

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 is the red → green loop. This skill is the reference that makes that loop produce tests worth keeping: what a good test is, where tests go, the anti-patterns, and the rules of the loop. Every section applies on every cycle: consult them before and during the loop, not after.

When exploring the codebase, read `GLOSSARY.md` (if it exists) so test names and interface vocabulary match the project's domain language, and respect ADRs in the area you're touching.

## What a good test is

Tests verify behavior through public interfaces, not implementation details. Code can change entirely; tests shouldn't. A good test reads like a specification: "user can checkout with valid cart" tells you exactly what capability exists, and it survives refactors because it doesn't care about internal structure.

See [tests.md](tests.md) for examples and [mocking.md](mocking.md) for mocking guidelines.

## Seams: where tests go

A **seam** is the public boundary you test at: the interface where you observe behavior without reaching inside. Tests live at seams, never against internals.
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add saifallah-star/aegis/tdd@sha256:c472c2a2b63bebad

The line at the top of this page pins the label git:20261016.0f9b29d, 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.

Badge

[![mdr](https://markdownregistry.com/badge/art_2kou5fbq3whyeaaf.svg)](https://markdownregistry.com/a/art_2kou5fbq3whyeaaf)

1 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 1 version of this file, committed on Oct 16, 2026.

version	committed	commit	size	audit
git:20261016.0f9b29d latest	2026-10-16	0f9b29d	3,738 B	A	view

Audit of the latest version

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 (3738 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

saifallah-star/aegis · 1 stars · license MIT · pushed 2026-10-29 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_2kou5fbq3whyeaaf
GET https://markdownregistry.com/api/v1/resolve?ref=saifallah-star/aegis/tdd
GET https://markdownregistry.com/api/v1/blob/c472c2a2b63bebadbbfeeae9efb37b50d90740be1c67e04dd543f61b9c31dbde

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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