Format and Lint on Every Save (rustfmt + clippy)

Why this matters

Rust has the same culture as Go: opinionated tools, no debates. rustfmt formats to one canonical style. clippy lints across hundreds of rules. Configure both via rustfmt.toml and clippy.toml (sparingly), wire them into your editor on save and into CI as gating checks. A team that ships rustfmt+clippy from day 1 has clean diffs forever; a team that doesn't will rage-quit within months.

Demo

rustfmt and clippy are the two guardrails that keep Rust codebases consistent and idiomatic. rustfmt enforces a canonical style automatically — no debate, just run it. clippy is a static analysis linter that catches hundreds of common mistakes, performance anti-patterns, and non-idiomatic constructs that the compiler itself won't flag. Wiring both into your CI pipeline with --check flags means every pull request is verified to be formatted and lint-clean before it merges.

Try it yourself

1. Run cargo fmt --all on the M1 hello project. If the diff is non-empty, you've found ungoverned formatting.
2. Run cargo clippy -- -D warnings (the -D makes warnings hard errors). Fix every finding.
3. Add a rustfmt.toml setting max_width = 100 (or 80 — pick a side). Reformat. Note how cargo fmt is now project-aware.
4. Wire both into a pre-commit hook (or husky-style if you have a JS toolchain). 4 lines of shell, saves hours of review nits.

References

• rustfmt config
• Clippy lint list
• Rust API Guidelines