rust-coding-standards

Use thiserror to define custom error enums with #[derive(Error)] for libraries, and anyhow with .context() for application-level error propagation. The ? operator automatically converts between error types using #[from] attributes.

Run the setup-rust-project.sh script with a project name and --lib or --bin flag. It creates the crate, copies rustfmt.toml and clippy.toml, adds standard dependencies, and generates a GitHub Actions workflow running tests, clippy, fmt, and cargo audit.

String is an owned, heap-allocated type while &str is a borrowed string slice. Prefer &str for function parameters to avoid unnecessary allocations, and use String when you need ownership or mutation.

Use the #[tokio::test] attribute on async test functions instead of #[test]. This runs the test on a tokio runtime, allowing you to .await async operations directly inside the test body.

Reserve unsafe for FFI calls, raw pointer manipulation, or implementing unsafe traits like Send and Sync. Always document safety invariants with a # Safety doc section, minimize unsafe block scope, and test with Miri to detect undefined behavior.

The borrow checker enforces one mutable reference XOR multiple immutable references at a time. Restructure code so borrows end before mutation, clone data when sharing is needed, or use Arc<Mutex<T>> for shared mutable state across tasks.