check-license.yml

# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/check-license.md
name: Check License

# See: https://docs.github.com/actions/using-workflows/events-that-trigger-workflows
on:
  create:
  push:
    paths:
      - ".github/workflows/check-license.ya?ml"
      # See: https://github.com/licensee/licensee/blob/master/docs/what-we-look-at.md#detecting-the-license-file
      - "[cC][oO][pP][yY][iI][nN][gG]*"
      - "[cC][oO][pP][yY][rR][iI][gG][hH][tH]*"
      - "[lL][iI][cC][eE][nN][cCsS][eE]*"
      - "[oO][fF][lL]*"
      - "[pP][aA][tT][eE][nN][tT][sS]*"
  pull_request:
    paths:
      - ".github/workflows/check-license.ya?ml"
      - "[cC][oO][pP][yY][iI][nN][gG]*"
      - "[cC][oO][pP][yY][rR][iI][gG][hH][tH]*"
      - "[lL][iI][cC][eE][nN][cCsS][eE]*"
      - "[oO][fF][lL]*"
      - "[pP][aA][tT][eE][nN][tT][sS]*"
  schedule:
    # Run periodically to catch breakage caused by external changes.
    - cron: "0 6 * * WED"
  workflow_dispatch:
  repository_dispatch:

jobs:
  run-determination:
    runs-on: ubuntu-latest
    permissions: {}
    outputs:
      result: ${{ steps.determination.outputs.result }}
    steps:
      - name: Determine if the rest of the workflow should run
        id: determination
        run: |
          RELEASE_BRANCH_REGEX="^refs/heads/v[0-9]+$"
          # The `create` event trigger doesn't support `branches` filters, so it's necessary to use Bash instead.
          if [[
            "${{ github.event_name }}" != "create" ||
            "${{ github.ref }}" =~ $RELEASE_BRANCH_REGEX
          ]]; then
            # Run the other jobs.
            RESULT="true"
          else
            # There is no need to run the other jobs.
            RESULT="false"
          fi

          echo "result=$RESULT" >> $GITHUB_OUTPUT

  check-license:
    name: ${{ matrix.check-license.path }}
    needs: run-determination
    if: needs.run-determination.outputs.result == 'true'
    runs-on: ubuntu-latest
    permissions:
      contents: read

    strategy:
      fail-fast: false

      matrix:
        check-license:
          - path: ./
            expected-filename: LICENSE.txt
            # SPDX identifier: https://spdx.org/licenses/
            expected-type: GPL-3.0

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Install Ruby
        uses: ruby/setup-ruby@v1
        with:
          ruby-version: ruby # Install latest version

      - name: Install licensee
        run: gem install licensee

      - name: Check license file for ${{ matrix.check-license.path }}
        run: |
          EXIT_STATUS=0

          # Go into folder path
          cd ./${{ matrix.check-license.path }}

          # See: https://github.com/licensee/licensee
          LICENSEE_OUTPUT="$(licensee detect --json --confidence=100)"

          DETECTED_LICENSE_FILE="$(echo "$LICENSEE_OUTPUT" | jq .matched_files[0].filename | tr --delete '\r')"
          echo "Detected license file: $DETECTED_LICENSE_FILE"
          if [ "$DETECTED_LICENSE_FILE" != "\"${{ matrix.check-license.expected-filename }}\"" ]; then
            echo "::error file=${DETECTED_LICENSE_FILE}::detected license file $DETECTED_LICENSE_FILE doesn't match expected: ${{ matrix.check-license.expected-filename }}"
            EXIT_STATUS=1
          fi

          DETECTED_LICENSE_TYPE="$(echo "$LICENSEE_OUTPUT" | jq .matched_files[0].matched_license | tr --delete '\r')"
          echo "Detected license type: $DETECTED_LICENSE_TYPE"
          if [ "$DETECTED_LICENSE_TYPE" != "\"${{ matrix.check-license.expected-type }}\"" ]; then
            echo "::error file=${DETECTED_LICENSE_FILE}::detected license type $DETECTED_LICENSE_TYPE doesn't match expected \"${{ matrix.check-license.expected-type }}\""
            EXIT_STATUS=1
          fi

          exit $EXIT_STATUS