GitHub Actions for Rust projects

Using ubuntu-latests, macos-latest, or windows-latests will automatically bring you the most recent stable version of the Rust compiler. see this example.

This is nice as you won't need to worry about updating it, but it has the obvious disadvantage that the rust compiler automatically changes without you making any change in the configuration.

Many projects use the actions-rs/toolchain, but it has been deprecated on October 13, 2023.

Many use dtolnay/rust-toolchain to set the toolchain(s) explicitely. You can either set a specific version number or you can use the words: stable for the most recent stable version, beta for the next version, nightly for wilde development efforts.

examples/github-workflows/matrix.yml

name: Matrix
on:
  - pull_request
  - push
jobs:
  main:
    strategy:
      matrix:
        rust:
          - stable
          - beta
          - nightly
          - 1.78
          - 1.88
    name: ${{matrix.rust}}
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@v1
        with:
          toolchain: ${{matrix.rust}}
          components: rustfmt, clippy
      - run: rustup --version
      - run: rustc -vV

      - run: cargo clippy -- --deny clippy::pedantic
      - run: cargo fmt --all -- --check
      - run: cargo test
        #      - run: cargo install cargo-tarpaulin && cargo tarpaulin --out Xml
        #      - uses: codecov/codecov-action@v1

GitHub Actions

Popular GitHub Actions used by Rust Crates.

• dtolnay/rust-toolchain to install the right toolchain(s), target(s), and component(s).

• bnjbvr/cargo-machete to remove unused Rust dependencies

• Swatinem/rust-cache smart caching for rust/cargo projects with sensible defaults to reduce compilation time.

Cargo commands

Various cargo commands I saw in the GitHub Workflows

cargo build --verbose

cargo test --verbose

cargo fmt
cargo fmt -- --check
cargo fmt -- --all --check

cargo clippy
cargo clippy -- --deny clippy::pedantic
cargo clippy --all-targets ${{ matrix.feature }} -- -D warnings
    // where the matrix.feature field can be ['', '--no-default-features', '--all-features']

cargo doc --no-deps --all-features

GitHub Workflow elements

env:
  CARGO_TERM_COLOR: always

Caching with the generic cache action

Using actions/cache (but see the rust-cachec above)

      - name: Cache cargo registry
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
            ~/.cargo/git
            target
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-

Verify git tag matches Cargo.toml version

      - name: Verify tag matches Cargo.toml version
        run: |
          TAG_VERSION=${GITHUB_REF#refs/tags/v}
          CARGO_VERSION=$(grep '^version = ' Cargo.toml | sed 's/version = "\(.*\)"/\1/')
          echo "Tag version: $TAG_VERSION"
          echo "Cargo.toml version: $CARGO_VERSION"
          if [ "$TAG_VERSION" != "$CARGO_VERSION" ]; then
            echo "Error: Tag version ($TAG_VERSION) does not match Cargo.toml version ($CARGO_VERSION)"
            exit 1
          fi

Publish to crates.io

      - name: Publish to crates.io
        run: cargo publish
        env:
          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_TOKEN }}