license-check.yml

# Automatically fix license files on PRs that need updates
# Instead of just failing, this workflow pushes the fix and comments on the PR

name: License Check
on:
  pull_request:
    paths:
      - "**.go"
      - go.mod
      - go.sum
      - ".github/licenses.tmpl"
      - "script/licenses*"
      - "third-party-licenses.*.md"
      - "third-party/**"
permissions:
  contents: write
  pull-requests: write

jobs:
  license-check:
    runs-on: ubuntu-latest
    # Don't run on forks (they can't push back) or dependabot
    if: github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]'

    steps:
      - name: Check out code
        uses: actions/checkout@v6
        with:
          ref: ${{ github.head_ref }}

      - name: Set up Go
        uses: actions/setup-go@v6
        with:
          go-version-file: "go.mod"

      # actions/setup-go does not setup the installed toolchain to be preferred over the system install,
      # which causes go-licenses to raise "Package ... does not have module info" errors.
      # For more information, https://github.com/google/go-licenses/issues/244#issuecomment-1885098633
      - name: Regenerate licenses
        env:
          CI: "true"
        run: |
          export GOROOT=$(go env GOROOT)
          export PATH=${GOROOT}/bin:$PATH
          ./script/licenses

      - name: Check for changes
        id: changes
        run: |
          if git diff --exit-code; then
            echo "changed=false" >> $GITHUB_OUTPUT
            echo "✅ License files are up to date"
          else
            echo "changed=true" >> $GITHUB_OUTPUT
            echo "📝 License files need updating"
            git diff --stat
          fi

      - name: Commit and push fixes
        if: steps.changes.outputs.changed == 'true'
        run: |
          git config --local user.name "github-actions[bot]"
          git config --local user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git add third-party third-party-licenses.*.md
          git commit -m "chore: regenerate third-party licenses"
          git push

      - name: Comment on PR
        if: steps.changes.outputs.changed == 'true'
        uses: actions/github-script@v7
        with:
          script: |
            github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body: `## 📜 License files updated

I noticed the third-party license files were out of date and pushed a fix to this PR.

**What changed:** Dependencies were added, removed, or updated, which requires regenerating the license documentation.

**What I did:** Ran \`./script/licenses\` and committed the result.

Please pull the latest changes before pushing again.`
            })