ryderfreeman4logos/cli-sub-agent/csa-rust-dev

Rust Development Excellence

Comprehensive guide for professional Rust development combining implementation expertise, architectural depth, and project standards.

Core Principles

Strategic Programming

Every design decision must answer: "Does this simplify system understanding, modification, and reasoning?"

• Build Deep Modules: Minimize public API surface, ruthlessly hide implementation details
• Type System as Shield: Make illegal states unrepresentable using Newtype patterns and discriminated unions
• Trait-Oriented Design: Program to interfaces (small, focused, composable), use async-trait for trait objects
• Error Handling Strategy:
• Libraries: FORBIDDEN unwrap()/expect(), use thiserror
• Applications: use anyhow for context
• Design errors out of existence when possible (e.g., delete non-existent file = no-op)
• Lifecycle Complexity: Push lifetimes into implementation, complex signatures in public APIs = RED FLAG

Code Quality Standards

Justfile Protocol (mandatory):

• Single source of truth: NO justfile in subdirectories
• Always use just when available
• Standard commands: fmt-all, clippy-all, test-all, check-han (Chinese character detection)

Documentation:

• Write /// docs BEFORE implementation
• Include runnable # Examples
• Document errors with # Errors section

Code Smells (refactor immediately):

• Excessive pub (shallow modules)
• Complex lifetimes in public APIs
• panic!/unwrap()/expect() in libraries
• Excessive .clone()
• Boolean parameters (use enum instead)

Development Workflow

Micro-Loop for Each Logical Unit

1. Code: Minimal functional increment
2. Format: just fmt-all
3. Lint: just clippy-all (ALL warnings must be fixed)
4. Test: just test-all, write necessary tests
5. Review: git diff self-review
6. Commit: Conventional Commits with motivation/implementation details

Commit Protocol

• Format: type(scope): description
• Body: [MOTIVATION], [IMPLEMENTATION DETAILS]
• Never use -S flag
• Repository config changes: separate commit

Project Defaults

Cargo.toml Configuration

[package]
edition = "2024"
rust-version = "1.85"
 
[lints.rust]
unsafe_code = "warn"
 
[lints.clippy]
all = "warn"
pedantic = "warn"

Unsafe Code Rule

Every unsafe block MUST have // SAFETY: comment explaining why it's safe.

Code Review Checklist

• [ ] No unwrap()/expect() in library code
• [ ] No complex lifetimes in public APIs
• [ ] Using enum instead of bool flags
• [ ] Appropriate error handling (thiserror/anyhow)
• [ ] Documentation with examples
• [ ] All clippy warnings resolved
• [ ] Tests written for new logic
• [ ] No Chinese characters in code/comments