Rust Development

Target Maintenance (on skill load)

Once per session, if target/ exists:

du -sh target && find target -type f -mtime +30 -print -quit

If size > ~1 GB AND find printed a path (it stops at the first hit): run cargo clean before building (the bloat is orphaned artifacts from old toolchains). Otherwise leave the warm cache alone. A rebuild resets the 30-day clock, so this self-limits.

Commands

• cargo build - Build (debug only)
• cargo test - Run tests
• cargo fmt - Format code (run after changes)
• cargo clippy - Lint (run after changes)

Dependencies

• MUST use cargo add <crate> to add dependencies - never manually edit Cargo.toml for dependencies
• ALWAYS ask the user for approval before adding any new dependency
• Only suggest well-known, widely-used crates with good maintenance records
• Prefer crates from the Rust ecosystem's trusted maintainers (e.g., tokio-rs, serde-rs, rust-lang)
• Check crate download counts and recent activity as indicators of reliability
• ALWAYS run cargo audit after adding a new dependency
• ALWAYS report any vulnerabilities or issues from cargo audit to the user - never silently ignore audit results

Toolchain

• Prefer stable Rust
• Use nightly only if required

Style

• Minimal comments, self-documenting code
• Concise implementations
• Discuss large refactors before starting

Error Handling

• Use judgment: unwrap/expect OK when clearer
• Match on errors when recovery is needed

Testing

• Unit tests with #[cfg(test)] module when asked
• Integration tests in separate files

Build

• NEVER make release builds (--release)
• Always use debug builds