Borrowing it
Nothing to install: this file belongs to jakubsuplicki/codument. 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/jakubsuplicki/codument/main/.agents/skills/tdd/SKILL.mdgit clone --depth 1 https://github.com/jakubsuplicki/codumentWrote 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/jakubsuplicki/codument/tdd)<a href="https://agentmods.dev/skills/jakubsuplicki/codument/tdd"><img src="https://agentmods.dev/badge/skills/jakubsuplicki/codument/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/jakubsuplicki/codument/tdd"><img src="https://agentmods.dev/badge/skills/jakubsuplicki/codument/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 | $0.00023 | $0.00628 |
| Opus 5.5 | $0.00009 | $0.00251 |
| Sonnet 5.5 | $0.00005 | $0.00126 |
| Haiku 4.5 | $0.00002 | $0.00063 |
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 23d 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
Use this when implementing a planned step or fixing a bug. The principle is feedback first: build the fastest reliable loop that proves the behavior.
Workflow
- Read the approved plan step and its mapped docs.
- Identify the plan's promised milestone and the user or integration boundary that supplies its acceptance evidence. Exercise a representative end-to-end experience early; supporting infrastructure names the milestone it unblocks.
- Choose the cheapest reliable feedback loop that exercises that boundary; use a small representative experiment before building expensive supporting infrastructure:
- Unit test for pure logic
- Integration test for module boundaries
- CLI invocation for command behavior
- Browser or UI harness for interface behavior
- Repro script for a bug when a proper test seam does not exist yet
- Prefer red-green-refactor:
- Red: write one failing behavior test
- Green: add the smallest code change that passes it
- Refactor: improve structure only while tests are green
- Repeat one behavior at a time.
- Update docs and registry when behavior or source ownership changes.
Evidence boundary
Record what was exercised, what was observed, and what remains untested. A mock, fake, or local executor supports only its exercised contract; it does not prove an external provider's behavior, downstream checks, or an end-to-end effect. Use the real integration when the approved acceptance criteria require it and it is available within the authorized scope. If it is unavailable, keep that criterion open, record the blocker, and bring any change to acceptance back to the user. A green local suite cannot silently replace required integration evidence.
An expected failure during the red phase is feedback, not a final verification failure. Once the relevant checks pass, broaden them only for required checks or a concrete unresolved concern; do not build a new harness for a reversible edit that an existing check can verify.
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.
- 23d ago Changed · +7 lines bd6321af2a61
- 1mo ago Changed · +6 lines 74f5b3831a98
- 1mo ago First seen · 43 lines · 23 tokens per session scan A 121de0703b9f
tdd is a skill published in the GitHub repository jakubsuplicki/codument (48 stars, last pushed 23d ago), licensed Apache-2.0. It adds 23 tokens to every session and 628 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 2026-08-30.
Other skills, from other repositories
testing
Use when implementing any feature or bugfix - before writing implementation code. Write the test first, watch it fail, then implement.
tdd
Enforces red-green-refactor TDD cycle with atomic commits per phase. Used when implementing features, fixing bugs, or when tests should drive the design.
skillshare-implement-feature
Implement a feature from a spec file or description using TDD workflow. Use this skill whenever the user asks to: add a new CLI command, implement a feature from a spec, build new functionality, add a flag, create a new internal package, or write Go code for skillshare. This skill enforces test-first development…
implement
Use when an approved plan and task list exist and it is time to turn them into working, tested code — the SDD phase after analyze and before verify. Enforces TDD: a failing test comes before the code that makes it pass, one task at a time, appended to a progress ledger that survives compaction. Delegates test tooling…
product
Consolidated Galyarder Framework Product intelligence bundle.
done
Close a SpecWeave increment - every task done or skipped, specweave verify green, a fresh-context review, then specweave complete. Use for "close it", "we are done", "finish up".