declaring-invariants 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.
declaring-invariants from oaustegard/claude-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add oaustegard/claude-skills/declaring-invariants@v0.2.3Pins v0.2.3 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- oaustegard/claude-skills
- Path
declaring-invariants/SKILL.md- Versions recorded
- 1
- Latest version
- v0.2.3, committed Aug 25, 2026
- Size
- 14,538 bytes
- Repository stars
- 158
- License
- MIT
Find tests that enumerate a domain by copying it, and declare the invariants a codebase depends on. Reports where a parametrize list, for-loop, or it.each iterates a hand-written subset of a dict/set/tuple/Enum that exists in the source, and names the members nothing covers. Use when reviewing tests, when a module gains a name-to-thing table, registry, enum, or dispatch map, before trusting a green suite as evidence a domain is covered, or when asked "is this test actually total…
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
# declaring-invariants Two scripts over one idea: **a test that enumerates a domain must loop the registry rather than a copy of it.** Someone also has to say which domains matter in the first place. ```bash python3 scripts/totality_lint.py <repo> # tests that copy a domain python3 scripts/claims.py <repo> # what the repo declares, and what backs it ``` Python only, stdlib `ast` only: no install, no config file, no network. ## The failure it catches A test that loops a hand-written list passes its runner and proves nothing about completeness. When the same members also exist as a registry in the source, the list is a copy, and the copy drifts the moment someone adds a member to the registry and not to the test. Nothing goes red. Measured on `oaustegard/remex`, 2026-08-24: adding a fourth member to `ROTATION_CODES` with no construction behind it left the **entire 267-test suite green**. Four separate tests looked total; each parametrized `["haar", "rht"]` against a three-member registry. Only a test that looped the registry itself caught it. Adapted from the meta-oracle in [`daniloc/coherence`](https://github.com/daniloc/coherence) …
Read the whole file at its exact version.
How to install
mdr add oaustegard/claude-skills/declaring-invariants@sha256:34d9da0e1e2ab1a4The line at the top of this page pins the label v0.2.3, 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_l3gknuhqydghgqyz)
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Versions
The registry has recorded 1 version of this file, committed on Aug 25, 2026.
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 (14538 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
oaustegard/claude-skills · 158 stars · license MIT · pushed 2026-11-07 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_l3gknuhqydghgqyz GET https://markdownregistry.com/api/v1/resolve?ref=oaustegard/claude-skills/declaring-invariants GET https://markdownregistry.com/api/v1/blob/34d9da0e1e2ab1a481f9c768133c541a4e4ec856e5942bd72d239ee7f653a725
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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