CRATEmPLATE

An opinionated cargo-generate template for Rust projects.

Usage

cargo generate gh:mlavrinenko/cratemplate
# or using nix:
nix run nixpkgs#cargo-generate -- generate --git https://github.com/mlavrinenko/cratemplate

You'll be prompted for project name, GitHub username, description, license, and crate kind (bin or lib).

What you get

Language & toolchain

• Rust 2024 edition, rust-toolchain.toml, rustfmt.toml, clippy at deny with clippy.toml thresholds
• Either kind of crate: a bin gets main.rs, a clap CLI, assert_cmd e2e tests and a cross-platform release matrix; a lib drops all of that and ships a publish-only release workflow

Quality gates

• Code coverage via cargo-llvm-cov (70% minimum) — it merges child-process profraw, so subprocess-based CLI tests actually attribute
• CRAP metric gate via cargo-crap
• Copy-paste gate via jscpd
• File size limits via linecop (500 lines Rust, 200 Markdown)
• Dependency drift detection via outdatty
• Unused dependency detection via cargo-machete
• Advisory, license and dependency-ban audit via cargo-deny
• MSRV asserted in CI against the rust-version in Cargo.toml
• Per-gate memoization via mmz: every arm of just check is skipped when its declared inputs are unchanged, which makes the just install-hooks pre-commit hook (a gate-freshness assertion, every commit) affordable

Testing

• Inline tests extraction via ejectest
• CLI integration testing with assert_cmd + predicates
• Mutation testing recipes via cargo-mutants (a dev aid, never a gate)

Error handling & CLI

• thiserror for library errors; for a bin, anyhow + clap 4 + env_logger

Nix dev environment

• Flake with nix develop (rustc, cargo, clippy, rustfmt, just, rust-analyzer, nixd, ...)
• direnv / .envrc for automatic shell activation
• Justfile with common recipes (just check, just test, just cover, just crap, ...)
• just install-hooks for a pre-commit gate

Docs & conventions

• CHANGELOG.md (Keep a Changelog + SemVer)
• CONTRIBUTING.md with detailed conventions
• AGENTS.md with rules for LLM agents
• Multiple license support (MIT / Apache-2.0 / dual / GPL-3.0-only)

CI/CD

• GitHub Actions: CI (checks, coverage, dependency audit, MSRV), Pages deployment, cross-platform release + crates.io publish, all with pinned actions
• dependabot.yml for automated action bumps

Template maintenance

After making changes to the template, validate that it still produces a working project:

just validate bin    # or: just validate lib
just mmz validate bin  # same, memoized — free when template/ is unchanged

This generates a project of that kind in a temp directory and runs fmt, clippy, tests, build, coverage, CRAP gate, file size checks, cargo-deny and a sandboxed nix build against it. It also asserts the gate wiring: a second just check must leave every gate-tagged mmz rule fresh, mmz --is-fresh --tag gate must then pass without running anything, and just install-hooks must produce an executable hook. An arm of just check with no rule in .mmz/config.yaml fails validation instead of shipping.

Both kinds are validated — CI matrices bin and lib — because an unvalidated template branch rots silently.