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 agentmods add rules/tyrchen/cursor-rust-rules/testinggit clone --depth 1 https://github.com/tyrchen/cursor-rust-rulesWhat 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 | $0.00000 | $0.04737 |
| Opus 5 | $0.00000 | $0.02368 |
| Sonnet 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 2d 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.
- 2d 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
angular-20
This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.
dev-standard
Apache Superset development standards and guidelines for Cursor IDE.
typescript
Changes to these high-fan-out internals can affect every message, delta, element, or rerun. Keep work in them minimal, and benchmark changes with representative stress-test apps.
coolify-ai-docs
Master reference to all Coolify AI documentation in .ai/ directory.
python_lib
Tips and guidelines specific to the development of the Streamlit Python library, not applicable to scripts and e2e tests.
specs
This directory contains product and tech specs for Streamlit features.