rust-testing-patterns

rust-testing-patterns is a skill for Claude Code, Codex from vladolaru/claude-code-plugins. It costs 52 tokens per session (1,391 once invoked), scanned A, original, MIT.

A collection of patterns for writing and reviewing Rust tests. It covers Rust's built-in test tools along with async tests, test doubles, property-based tests, snapshots, and benchmarks.

In plain words
What is it for?
Use it when writing or reviewing Rust tests, testing asynchronous code, using mocks, checking many generated inputs, comparing snapshots, or measuring performance.
Why use it?
It helps you choose suitable Rust testing techniques and spot tests that are fragile or poorly isolated. It also supports behavior-focused testing rather than checking implementation details.

Skill for Claude CodeCodex

Part of the pirategoat-tools plugin — 22 skills shipped together

Install

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.

agentmods
npx agentmods add skills/vladolaru/claude-code-plugins/rust-testing-patterns
Any agent
npx skills add vladolaru/claude-code-plugins --skill rust-testing-patterns
Clone the repo
git clone --depth 1 https://github.com/vladolaru/claude-code-plugins

Made for: Claude Code, Codex.

Or install pirategoat-tools, the plugin that ships this one along with the rest of its 22 skills.

Wrote 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.

agentmods badge for rust-testing-patterns

README.md
[![agentmods](https://agentmods.dev/badge/skills/vladolaru/claude-code-plugins/rust-testing-patterns.svg)](https://agentmods.dev/skills/vladolaru/claude-code-plugins/rust-testing-patterns)
Your own site
<a href="https://agentmods.dev/skills/vladolaru/claude-code-plugins/rust-testing-patterns"><img src="https://agentmods.dev/badge/skills/vladolaru/claude-code-plugins/rust-testing-patterns.svg" alt="Measured on agentmods" height="20"></a>
Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,391 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00052 $0.01391
Opus 5 $0.00026 $0.00696
Sonnet 5 $0.00010 $0.00278
Haiku 4.5 $0.00005 $0.00139

Measured yesterday against content hash d60408a07d56, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rust-testing-patterns 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 yesterday.

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.

plugins/pirategoat-tools/skills/rust-testing-patterns/SKILL.md · 118 lines

How it starts

The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill Directory

Resolve SKILL_DIR to the absolute directory containing this SKILL.md, as shown by the current host, before using any bundled path below. Before a shell command uses $SKILL_DIR, assign it in that command or replace it with the resolved path. It is not a host-exported environment variable.

Rust Testing Patterns

Apply these Rust testing patterns when writing or reviewing tests. Flag red flags during review. Use the assertion quick reference when writing assertions. For shared test quality principles (philosophy, smells, mocking decisions), see testing-patterns.

Reference Routing

Need Reference File Sections to Read
Rust testing patterns $SKILL_DIR/../testing-patterns/references/rust-testing-patterns.md Full file (~350L, manageable)
Behavior vs implementation $SKILL_DIR/../testing-patterns/references/test-philosophy.md ## The Fundamental Shift + ## Four Core Principles
Flaky/brittle tests $SKILL_DIR/../testing-patterns/references/test-smells.md ## The Six Major Test Smells (relevant subsection)
Mock usage decisions $SKILL_DIR/../testing-patterns/references/mocking-strategies.md ## The Mocking Decision Framework
AAA pattern/naming $SKILL_DIR/../testing-patterns/references/test-structure.md ## The AAA Pattern + ## Test Naming Conventions
Test data strategy $SKILL_DIR/../testing-patterns/references/test-data.md ## Factories + ## Builders

How to read sections: Grep for heading to find line number, Read with offset+limit.

Rust Assertion Quick Reference

Use Instead Of Why
assert_eq!(got, want) assert!(got == want) Diff output on failure
assert!(result.is_err()) #[should_panic] Explicit, no false positives
result.unwrap_err() + assert #[should_panic(expected = "...")] Better failure messages
prop_assert!(expr) assert!(expr) in proptest Integrates with shrinking
tempfile::TempDir fs::create_dir("/tmp/...") RAII cleanup, no collisions
#[serial] -- --test-threads=1 Granular, per-resource isolation
#[tokio::test(flavor = "multi_thread")] #[tokio::test] for concurrency Catches race conditions

Read the full file on GitHub · 118 lines

Changes

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.

  1. yesterday First seen · 118 lines · 52 tokens per session scan A d60408a07d56

Subscribe to this mod's changes

rust-testing-patterns is a skill published in the GitHub repository vladolaru/claude-code-plugins (8 stars, last pushed yesterday), licensed MIT. It adds 52 tokens to every session and 1,391 once invoked, about $0.0003 per session on Opus 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.

Related

Other skills, from other repositories

run-helix-tests

Submit and monitor .NET MAUI unit tests on Helix infrastructure. Supports running XAML, Resizetizer, Core, Essentials, and other unit test projects on distributed Helix queues.

dotnet/maui · 45 tokens

migrate-xunit-to-xunit-v3

Migrate .NET test projects from xUnit.net v2 to xunit.v3 and fix v3 breaks. Use for package/CPM conversion, OutputType=Exe, preserving the VSTest or MTP runner (including projects currently using YTest.MTP.XUnit2), incompatible TFMs, async void tests, string-to-Type attributes, custom Fact/Theory/BeforeAfterTest…

dotnet/skills · 149 tokens

golang-testing

Production-ready Golang tests — table-driven tests, testify suites and mocks, parallel tests, fuzzing, fixtures, goroutine leak detection with goleak, snapshot testing, code coverage, integration tests, idiomatic test naming. Use when writing or reviewing Go tests, choosing a testing approach, setting up Go test CI…

samber/cc-skills-golang · 115 tokens

nunit-testing

Use when writing or modifying tests in NUnit's own test projects, or when making a behavioral change to production code that needs test coverage. Covers test structure, attribute choice, helper visibility, platform guards, and which test projects are real.

nunit/nunit · 51 tokens

detect-flaky-tests

Detects flaky Go tests by analyzing GitHub Actions workflow runs across the last 7 days and all PRs — covering both the run-tests job (unit/integration) and the e2e-test job (gVisor and microVM lanes). For each newly-detected flaky test or infra issue, opens a GitHub issue with full evidence and a draft fix PR. Does…

agent-substrate/substrate · 102 tokens

go-testing

Trigger: Go tests, go test coverage, Bubbletea teatest, golden files. Apply focused Go testing patterns.

Gentleman-Programming/gentle-ai · 26 tokens