Borrowing it
Nothing to install: this file belongs to stainless-code/codemap. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/stainless-code/codemap/main/.agents/skills/tdd/SKILL.mdgit clone --depth 1 https://github.com/stainless-code/codemapWrote 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.
[](https://agentmods.dev/skills/stainless-code/codemap/tdd)<a href="https://agentmods.dev/skills/stainless-code/codemap/tdd"><img src="https://agentmods.dev/badge/skills/stainless-code/codemap/tdd/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/stainless-code/codemap/tdd"><img src="https://agentmods.dev/badge/skills/stainless-code/codemap/tdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00032 | $0.00672 |
| Opus 5.5 | $0.00013 | $0.00269 |
| Sonnet 5.5 | $0.00006 | $0.00134 |
| Haiku 4.5 | $0.00003 | $0.00067 |
Grade A, and why
tdd 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test-driven development
Vertical RED→GREEN cycles — one behavior per loop, not horizontal "all tests then all code". Aligns with tracer-bullets and verify-after-each-step.
This repo
- Runner split per
docs/testing-coverage.md:bun test ./src— co-located unit tests (parsers, DB, engines, CLI/MCP handlers). Mock at parser/DB seams.bun run test:golden— indexfixtures/minimal, run SQL scenarios vs committed goldens.bun run test:scripts—scripts/**/*.test.mjs.bun run test:agent-eval— probe/live agent eval harness (after golden index when applicable).
- Co-locate tests next to the module (
src/db.ts→src/db.test.ts). - After each GREEN: format/lint/typecheck per
verify-after-each-step. - Mock at the parser or DB seam (fake
:memory:DB, stub adapter input), never inside the engine under test. SeePATTERNS.md.
Workflow
1. Planning
Confirm behaviors to test (not implementation steps) with the user. Prefer deep modules — small public surface (extractFileData, batchInsert, a recipe handler), complex internals.
2. Tracer bullet (within slice)
RED: one test for first behavior → bun test <file> (or test:golden when recipe/SQL output is the contract)
GREEN: minimal code to pass → re-run
3. Incremental loop
For each behavior: RED → GREEN → run affected tests. One test at a time; no speculative features.
4. Refactor
After GREEN — look for duplication, long methods, shallow modules, feature envy. Run bun test <file> after each step. Never refactor while RED. For production polish on a completed slice, harden-pr lite may run in parallel with tracer-bullet commits.
Checklist per cycle
[ ] Test describes behavior, not implementation
[ ] Test uses the public seam only (parser entry, DB insert path, CLI handler, recipe output)
[ ] Test would survive an internal refactor
[ ] Code is minimal for this test
[ ] bun test (or test:golden / test:scripts) passes on touched file(s)
What ships with it
1 file 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.
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.
- 1mo ago First seen · 56 lines · 32 tokens per session scan A 8bf221d47570
tdd is a skill published in the GitHub repository stainless-code/codemap (8 stars, last pushed yesterday), licensed MIT. It adds 32 tokens to every session and 672 once invoked, about $0.0001 per session on Opus 5.5. 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.
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Use when the user explicitly requests strict or test-first TDD, or when the current conversation already contains an explicit TDD Route: strict decision from another Aegis workflow.