write-tests SKILL.md skillA
This file is byte-identical to the first copy the registry indexed. Same content hash, so the same checks give both the same grade.
write-tests from dzhng/duet-agent is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dzhng/duet-agent/write-tests@git:20261021.e955131Pins git:20261021.e955131 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dzhng/duet-agent
- Path
.agents/skills/write-tests/SKILL.md- Versions recorded
- 5
- Latest version
- git:20261021.e955131, committed Oct 21, 2026
- First version recorded
- Jul 17, 2026
- Size
- 10,174 bytes
- Repository stars
- 50
- License
- Apache-2.0
Write tests that pin real behavior instead of implementation details, config values, or lucky samples. Use when adding tests for new behavior, writing a regression test, fixing a brittle or flaky test, reviewing a test diff, or when a test breaks after a refactor or config change that didn't change behavior.
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
# Write Tests A good test fails **only** when real behavior breaks, and passes through every refactor or config change that preserves it. Most bad tests fail the opposite way: red on harmless changes, green while the real path is broken. Every rule below serves that one goal. Default to end-to-end or system-level tests for regression coverage; use a unit test only for specific, complex business logic when fast feedback will materially speed development. For deciding whether coverage adds independent proof, where it belongs, or which existing tests can go, use [audit-tests](../audit-tests/SKILL.md). ## Workflow: tracer bullets, not a batch 1. **Write ONE test at a time.** Assert first, watch it go red on the un-fixed code, make the code earn green, learn, then write the next. Never a batch up front: a batch written against *imagined* behavior pins what you guessed — those tests pass when the mechanism breaks and fail when it's fine. Each green cycle tells you what the next test should actually assert. 2. **Iterate on the fastest focused runner** (one file, one test name), and run the full suite only as a final gate before handing off. Check the exit code, …
Read the whole file at its exact version.
How to install
mdr add dzhng/duet-agent/write-tests@sha256:536d98be60ecca39The line at the top of this page pins the label git:20261021.e955131, 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.
[](https://markdownregistry.com/a/art_lwcm5wemyff6bbar)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between Jul 17, 2026 and Oct 21, 2026, about one every 24 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261021.e955131 latest | 2026-10-21 | e955131 | 10,174 B | A | view · diff |
| git:20261015.2b8e6b5 | 2026-10-15 | 2b8e6b5 | 10,014 B | A | view · diff |
| git:20261002.7680dea | 2026-10-02 | 7680dea | 9,484 B | A | view · diff |
| git:20260917.2361b0a | 2026-09-17 | 2361b0a | 9,335 B | A | view · diff |
| git:20260717.934babf | 2026-07-17 | 934babf | 7,692 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (10174 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
dzhng/duet-agent · 50 stars · license Apache-2.0 · pushed 2026-10-21 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_lwcm5wemyff6bbar GET https://markdownregistry.com/api/v1/resolve?ref=dzhng/duet-agent/write-tests GET https://markdownregistry.com/api/v1/blob/536d98be60ecca39eadd936b7720d5242d6856faf24098a33ec4e1d92f1be4c5
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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