Agent Skills: rust-testing-code-review

Reviews Rust test code for unit test patterns, integration test structure, async testing, mocking approaches, and property-based testing. Covers Rust 2024 edition changes including async fn in traits for mocks, #[expect] lint suppression, LazyLock test fixtures, and temporary scope changes affecting test assertions. Use when reviewing _test.rs files, #[cfg(test)] modules, or test infrastructure in Rust projects. Covers tokio::test, test fixtures, and assertion patterns.