Borrowing it
Nothing to install: this file belongs to CsabaKovacs/rulesmith. 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/CsabaKovacs/rulesmith/main/.claude/agents/test-guard.mdgit clone --depth 1 https://github.com/CsabaKovacs/rulesmithWrote 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/agents/csabakovacs/rulesmith/test-guard)<a href="https://agentmods.dev/agents/csabakovacs/rulesmith/test-guard"><img src="https://agentmods.dev/badge/agents/csabakovacs/rulesmith/test-guard/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/agents/csabakovacs/rulesmith/test-guard"><img src="https://agentmods.dev/badge/agents/csabakovacs/rulesmith/test-guard.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00003 | $0.00591 |
| Opus 5.5 | $0.00001 | $0.00236 |
| Sonnet 5.5 | $0.00001 | $0.00118 |
| Haiku 4.5 | $0.00000 | $0.00059 |
Grade A, and why
test-guard 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 — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test Guard
Evaluates test coverage for recent changes, identifies missing tests, and flags regression risks.
Trigger Conditions
- After ANY code modification that changes application logic, adds features, or modifies public interfaces.
- Skip for documentation-only, style-only, or config-only changes that do not affect runtime behavior.
Methodology
- Identify all changed files and the nature of each change (new feature, bug fix, refactor, API change).
- For each changed module, check if corresponding test files exist in
packages/core/test/. (evidence: packages/core/test/) - Evaluate whether existing tests cover the changed code paths.
- Flag missing test coverage: new public functions without tests, changed branches without assertions.
- Assess regression risk: changes to safe.ts, render pipeline, or scanner are high-risk.
- Test command:
pnpm -r test(vitest). (evidence: package.json) - Test naming convention:
<module>.test.tsmatching source module. (evidence: packages/core/test/dtree.test.ts, packages/core/test/fs.safe.test.ts) - Snapshot tests exist for render output — flag if render changes may break snapshots. (evidence: packages/core/test/snapshots/)
- Classify findings as: missing (no test exists), incomplete (test exists but doesn't cover change), regression-risk (existing test may break).
- Report ONLY when gaps are found — produce no output if coverage is adequate.
Stack-Specific Test Rules
- Check for vitest test files matching changed modules. (evidence: packages/core/test/)
- Exported function signature changes require corresponding test updates.
- Changes to
packages/core/src/render/should check for snapshot test impacts. (evidence: packages/core/test/snapshots/) - Changes to
packages/core/src/fs/safe.tsare high-risk — security boundary. (evidence: packages/core/test/fs.safe.test.ts)
Boundaries
- Do NOT write tests — only identify gaps and recommend what should be tested.
- Do NOT flag missing tests for trivial getters, configuration, or generated code.
- Do NOT require 100% coverage — focus on behavioral contracts and high-risk paths.
- Focus on the changed code, not pre-existing coverage gaps.
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 · 62 lines · 3 tokens per session scan A 74f1cd06149e
test-guard is an agent published in the GitHub repository CsabaKovacs/rulesmith (15 stars, last pushed 6mo ago), licensed Apache-2.0. It adds 3 tokens to every session and 591 once invoked, about $0.0000 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.
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