rust-coding-standards

name	rust-coding-standards
description	Use when writing, reviewing, or refactoring Rust code. Provides type safety patterns, error handling, project layout, and async programming guidelines.
allowed-tools	Read, Grep, Glob

Rust Coding Standards

This skill provides modern Rust coding guidelines and best practices for this project.

When to Apply

Apply these standards when:

• Writing new Rust code
• Reviewing or refactoring existing Rust code
• Designing module APIs and public interfaces
• Implementing error handling strategies

Core Principles

1. Ownership Over Copying - Leverage Rust's ownership system, avoid unnecessary clones
2. Explicit Over Implicit - Make types and intentions clear
3. Simple Over Clever - Prefer readable code over clever abstractions
4. Fail Fast - Catch errors at compile time via strong typing

Quick Reference

Must-Use Patterns

Pattern	Use Case
Newtype pattern	IDs, validated strings, domain types
Result<T, E>	All fallible operations
#[must_use]	Functions where ignoring return is likely a bug
#[non_exhaustive]	Public enums that may gain variants
Builder pattern	Complex struct construction
Type state pattern	Compile-time state machine validation

Must-Avoid Anti-Patterns

Anti-Pattern	Alternative
.unwrap() in production	? operator or explicit handling
panic! for expected failures	Return Result<T, E>
String for all text	Newtype wrappers for semantic meaning
Deep module nesting (>3 levels)	Flat, feature-based structure
pub on everything	Minimal public API surface
clone() to satisfy borrow checker	Restructure ownership

Detailed Guidelines

For comprehensive guidance, see:

• Error Handling Patterns - Result, Option, thiserror, anyhow
• Type Safety Best Practices - Newtype pattern, type state, lifetimes
• Project Layout Conventions - Cargo workspace, module structure
• Async Programming Patterns - tokio, async/await, channels
• Security Guidelines - Credential protection, path sanitization, sensitive data handling

Clippy Configuration

This project uses strict Clippy linting. Ensure your code passes:

cargo clippy --all-targets -- -D warnings

Common Clippy lints enabled:

• clippy::pedantic - Extra strictness
• clippy::nursery - Experimental lints
• clippy::unwrap_used - Disallow unwrap in production
• clippy::expect_used - Disallow expect in production

Rustfmt Configuration

If present, rustfmt.toml defines formatting rules:

edition = "2021"
max_width = 100
use_small_heuristics = "Max"

References

• Rust API Guidelines
• Effective Rust
• Rust Design Patterns
• The Rust Performance Book