check-whitespace.yml

name: check-whitespace

# Get the repository with all commits to ensure that we can analyze
# all of the commits contributed via the Pull Request.
# Process `git log --check` output to extract just the check errors.
# Exit with failure upon white-space issues.

on:
  pull_request:
    types: [opened, synchronize]

jobs:
  check-whitespace:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0

      - name: git log --check
        id: check_out
        run: |
          log=
          commit=
          while read dash etc
          do
            case "${dash}" in
            "---")
              commit="${etc}"
              ;;
            "")
              ;;
            *)
              if test -n "${commit}"
              then
                log="${log}\n${commit}"
                echo ""
                echo "--- ${commit}"
              fi
              commit=
              log="${log}\n${dash} ${etc}"
              echo "${dash} ${etc}"
              ;;
            esac
          done <<< $(git log --check --pretty=format:"---% h% s" ${{github.event.pull_request.base.sha}}..)
          if test -n "${log}"
          then
            exit 2
          fi