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.
git clone --depth 1 https://github.com/tyrchen/cursor-rust-rulesWrote 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/rules/tyrchen/cursor-rust-rules/testing)<a href="https://agentmods.dev/rules/tyrchen/cursor-rust-rules/testing"><img src="https://agentmods.dev/badge/rules/tyrchen/cursor-rust-rules/testing/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/rules/tyrchen/cursor-rust-rules/testing"><img src="https://agentmods.dev/badge/rules/tyrchen/cursor-rust-rules/testing.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 | $0.00000 | $0.04737 |
| Opus 5.5 | $0.00000 | $0.01895 |
| Sonnet 5.5 | $0.00000 | $0.00947 |
| Haiku 4.5 | $0.00000 | $0.00474 |
Grade A, and why
testing 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 — 677 lines — stays where its author put it; the contents beside it link to each section on GitHub.
🧪 RUST TESTING STANDARDS
TL;DR: Comprehensive testing guidelines for Rust projects covering unit tests, integration tests, property testing, benchmarks, and CI integration with best practices for test organization and coverage.
🔍 TESTING STRATEGY SELECTION
graph TD
Start["Testing Requirements"] --> Strategy{"Testing Strategy?"}
Strategy -->|"Unit Testing"| Unit["Unit Tests"]
Strategy -->|"Integration Testing"| Integration["Integration Tests"]
Strategy -->|"Property Testing"| Property["Property Testing"]
Strategy -->|"Benchmarking"| Benchmark["Performance Benchmarks"]
Strategy -->|"End-to-End Testing"| E2E["E2E Tests"]
Unit --> UnitFeatures["Unit Test Features:"]
Integration --> IntegrationFeatures["Integration Features:"]
Property --> PropertyFeatures["Property Features:"]
Benchmark --> BenchmarkFeatures["Benchmark Features:"]
E2E --> E2EFeatures["E2E Features:"]
UnitFeatures --> UnitItems["• Individual function testing<br>• Mock dependencies<br>• Fast execution<br>• High coverage"]
IntegrationFeatures --> IntegrationItems["• Multi-module testing<br>• Real dependencies<br>• Realistic scenarios<br>• API testing"]
PropertyFeatures --> PropertyItems["• Random input testing<br>• Edge case discovery<br>• Invariant verification<br>• Fuzzing"]
BenchmarkFeatures --> BenchmarkItems["• Performance regression<br>• Memory usage tracking<br>• Throughput measurement<br>• Optimization validation"]
E2EFeatures --> E2EItems["• Full system testing<br>• User workflow validation<br>• External service mocking<br>• Production-like environment"]
UnitItems --> Tools["Testing Tools"]
IntegrationItems --> Tools
PropertyItems --> Tools
BenchmarkItems --> Tools
E2EItems --> Tools
Tools --> MockTool["Mocking: mockall"]
Tools --> PropertyTool["Property: proptest"]
Tools --> BenchTool["Benchmarks: criterion"]
Tools --> WebTool["Web Testing: axum-test"]
Tools --> HttpTool["HTTP Mocking: wiremock"]
style Start fill:#4da6ff,stroke:#0066cc,color:white
style Strategy fill:#ffa64d,stroke:#cc7a30,color:white
style Unit fill:#4dbb5f,stroke:#36873f,color:white
style Integration fill:#d94dbb,stroke:#a3378a,color:white
style Property fill:#9f4dbb,stroke:#7a3787,color:white
style Benchmark fill:#bb4d4d,stroke:#873636,color:white
style E2E fill:#bbbb4d,stroke:#878736,color:white
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 · 677 lines · 0 tokens per session scan A cf4d41f5b703
testing is a cursor rule published in the GitHub repository tyrchen/cursor-rust-rules (27 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 4,737 tokens. 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.
Other cursor rules, from other repositories
testing
Testing guidelines and patterns for skia-rs.
threaded-test-timeout
Threaded tests need timeouts.
rust-testing
Rust Testing Best Practices.
test-quality-validation
Validates test quality and prevents testing theater anti-patterns in Rust test files.
mcp-server-attr-codegen-test
A set of Cursor coding rules for testing generated code from a Rust Model Context Protocol server attribute system. Code generation means producing source code automatically from declarations or annotations.
core_test_isolation
A testing rule for Tauri applications that use an LLM, such as an agent, tool-calling system, or chat. Tauri is a framework for desktop apps, and the rule keeps agent logic in a separate Rust workspace package from the app shell.