Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add fusengine/agents --skill rust-testing-qualitygit clone --depth 1 https://github.com/fusengine/agentsWrote 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/fusengine/agents/rust-testing-quality)<a href="https://agentmods.dev/skills/fusengine/agents/rust-testing-quality"><img src="https://agentmods.dev/badge/skills/fusengine/agents/rust-testing-quality/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/fusengine/agents/rust-testing-quality"><img src="https://agentmods.dev/badge/skills/fusengine/agents/rust-testing-quality.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 | $0.00046 | $0.01264 |
| Opus 5.5 | $0.00018 | $0.00506 |
| Sonnet 5.5 | $0.00009 | $0.00253 |
| Haiku 4.5 | $0.00005 | $0.00126 |
Grade A, and why
rust-testing-quality 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 22d 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 — 138 lines — stays where its author put it; the contents beside it link to each section on GitHub.
It also covers the nextest doctest pitfall: cargo nextest run never runs doc-tests, so
cargo test --doc must always be paired alongside it — a green nextest run alone is not
full coverage.
Out of scope: CI pipeline wiring and gate ordering belong to rust-tooling-cicd; non-Rust test suites are not covered.
Rust Testing & Quality
Agent Workflow (MANDATORY)
Before ANY test work, spawn 3 agents in parallel, one Agent call each with a name:
- fuse-ai-pilot:explore-codebase - Map existing
tests/,#[cfg(test)],benches/ - fuse-ai-pilot:research-expert - Verify current nextest/proptest/criterion docs via Context7/Exa
- mcp__context7__query-docs - Check crate-specific API (proptest strategies, criterion groups)
After implementation, run fuse-ai-pilot:sniper for validation.
Overview
| Test kind | Location | Runs the code as |
|---|---|---|
| Unit | #[cfg(test)] mod tests inside the source file |
Same crate, sees private items |
| Integration | tests/*.rs (each file = own crate) |
External consumer, public API only |
| Doc-test | ```rust blocks in /// docs |
Compiled + run as examples |
| Property | proptest, inside unit or integration | Generated random inputs + shrinking |
| Benchmark | benches/*.rs with criterion |
Statistical timing, not correctness |
Critical Rules
- nextest does NOT run doc-tests -
cargo nextest runskips them by design. ALWAYS pair withcargo test --doc. Never treat a green nextest run as full coverage. - Integration tests see only the public API - if a test needs private items, it belongs in
#[cfg(test)], nottests/. - Commit
proptest-regressions/- persisted failing seeds must be under version control so failures are reproducible. harness = falsefor criterion benches - required inCargo.toml, or the built-in bench harness collides.- Mutation testing is a gate, not a smoke test -
cargo mutantsis slow; run it in scheduled CI, not on every push.
What ships with it
5 files 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.
- 22d ago Changed dffee6b6adc4
- 1mo ago Changed 9dc0df6bfc92
- 1mo ago First seen · 138 lines · 46 tokens per session scan A 516d8a008788
rust-testing-quality is a skill published in the GitHub repository fusengine/agents (33 stars, last pushed 7d ago), licensed MIT. It adds 46 tokens to every session and 1,264 once invoked, about $0.0002 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 2026-09-03.
Other skills, from other repositories
r-testthat
Best practices for writing R package tests with testthat version 3+. Use this skill when writing or organizing tests for an R package or when improving existing tests that use testthat. It covers test structure and expectations, self-sufficient test design, proper cleanup with withr, fixtures, mocking external…
craft-pest
Testing Craft CMS 5 plugins and modules with Pest — test isolation, database safety, and the markhuot/craft-pest-core harness. ALWAYS load when writing, running, fixing, or reviewing tests for a Craft plugin or module, and whenever a suite touches a real Craft install. Covers why rollback is opt-in, tests/Pest.php +…
rust-testing
Design Rust tests that catch real regressions — unit, integration, doc, property, snapshot, and golden tests, and differential tests that prove a port matches its source. Use when writing or reviewing Rust tests, when a change lands without tests, when deciding what form a test should take, when a port needs parity…
phx-verify
Verify Elixir/Phoenix changes — compile, format, and test in one loop. Use after implementation, before PRs, or after fixing bugs.
111-java-maven-dependencies
Use when you need to add or evaluate Maven dependencies that improve code quality or domain modeling — including nullness annotations (JSpecify), static analysis (Error Prone + NullAway), functional programming (VAVR), architecture testing (ArchUnit), or money and currency support (JavaMoney) — and want a…
130-java-testing-strategies
Use when you need to apply testing strategies for Java code — RIGHT-BICEP to guide test creation, A-TRIP for test quality characteristics, or CORRECT for verifying boundary conditions. This should trigger for requests such as Review Java code for testing strategies; Apply RIGHT-BICEP testing strategies in Java code…