ci.yaml

name: CI
on: merge_group

jobs:

  test:
    name: Test
    runs-on: ubuntu-latest
    strategy:
      matrix:
        rust: [
          1.31.0, # MSRV
          stable,
          beta,
          nightly,
        ]
    steps:
      - uses: actions/checkout@v4
      - uses: actions/cache@v4
        if: startsWith(matrix.rust, '1')
        with:
          path: ~/.cargo/registry/index
          key: cargo-${{ matrix.rust }}-git-index
      - uses: dtolnay/rust-toolchain@master
        with:
          toolchain: ${{ matrix.rust }}
      - run: cargo build
      - run: ./ci/test_full.sh

  # try a target that doesn't have std at all
  no_std:
    name: No Std
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
        with:
          target: thumbv6m-none-eabi
      - run: cargo build --target thumbv6m-none-eabi --no-default-features

  fmt:
    name: Format
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@1.62.0
        with:
          components: rustfmt
      - run: cargo fmt --all --check

  # One job that "summarizes" the success state of this pipeline. This can then be added to branch
  # protection, rather than having to add each job separately.
  success:
    name: Success
    runs-on: ubuntu-latest
    needs: [test, no_std, fmt]
    # Github branch protection is exceedingly silly and treats "jobs skipped because a dependency
    # failed" as success. So we have to do some contortions to ensure the job fails if any of its
    # dependencies fails.
    if: always() # make sure this is never "skipped"
    steps:
      # Manually check the status of all dependencies. `if: failure()` does not work.
      - name: check if any dependency failed
        run: jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'