Rust Best Practices
Use the existing crate design, edition, rust-toolchain.toml, and Cargo.toml rust-version (MSRV). Reference examples may use newer features: confirm support before adopting them; do not upgrade the toolchain or add a crate just to follow an example.
Read the reference for the Rust concern being changed. A local edit does not require every category, a new test framework, or a workspace-wide audit.
| Topic | Reference | Load When |
|---|---|---|
| Coding Style | references/coding-style.md | Naming, imports, iterators, comments, string handling, macros |
| Error Handling | references/error-handling.md | Result, Option, ?, thiserror, anyhow, custom errors, async errors |
| Ownership & Pointers | references/ownership-and-pointers.md | Lifetimes, borrowing, smart pointers, Pin, Cow, interior mutability |
| Traits & Generics | references/traits-and-generics.md | Trait design, dispatch, GATs, sealed traits, type state pattern |
| Async & Concurrency | references/async-and-concurrency.md | Tokio, channels, streams, shutdown, runtime config, async traits |
| Sync Concurrency | references/concurrency-sync.md | Atomics, Mutex, RwLock, lock ordering, Send/Sync, memory ordering |
| Testing | references/testing.md | Unit/integration/doc tests, snapshot, proptest, mockall, benchmarks, fuzz |
| Performance | references/performance.md | Profiling, flamegraph, cloning, stack vs heap, iterators, allocation |
| Clippy & Linting | references/clippy-and-linting.md | Clippy config, key lints, workspace setup, #[expect] vs #[allow] |
| Documentation | references/documentation.md | Doc comments, rustdoc, doc lints, coverage checklist |
Engineering floor
- Borrow or transfer ownership deliberately; clone when independent ownership is needed. Prefer clear ownership over numeric size rules or avoiding every allocation.
- Handle fallible operations with
Resultand preserve useful error context. Reserve panic/assertions for violated programmer invariants; validate external input with recoverable errors. - Match error types, dispatch, and dependencies to the existing public contract.
thiserror,anyhow, Tokio, and third-party synchronization crates are options, not mandatory additions. - Keep lock lifetimes short, maintain lock order, and reason about cancellation, shutdown, and spawned-task ownership. Do not hold a synchronous lock across
.await. - Treat
Send/Syncbounds and atomic orderings as correctness properties. Choose weaker ordering only with a valid synchronization argument; benchmark before performance-driven rewrites. - Put behavior tests in the suite that owns the invariant. Add type-level, property, fuzz, snapshot, or benchmark tests when that contract or risk warrants them.
- Run the repository's required scoped format, lint, and test commands; reuse valid evidence. Full workspace/all-feature runs and documentation coverage rules follow project policy. Check feature combinations actually supported by the crate.