pr-conventional-commits.yml

name: PR Conventional Commits Check

on:
  pull_request:
    branches: [main]
    types: [opened, synchronize, reopened, edited]

jobs:
  validate-commits:
    runs-on: ubuntu-latest
    # Skip validation for Release Please PRs (auto-generated)
    if: |
      !startsWith(github.event.pull_request.title, 'chore(main): release') &&
      !contains(github.event.pull_request.labels.*.name, 'autorelease: pending')
    permissions:
      contents: read
      pull-requests: write
      statuses: write
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Cache npm dependencies
        uses: actions/cache@v4
        with:
          path: ~/.npm
          key: ${{ runner.os }}-commitlint-${{ hashFiles('.github/workflows/pr-conventional-commits.yml') }}
          restore-keys: |
            ${{ runner.os }}-commitlint-

      - name: Install Commitlint
        run: npm install --save-dev @commitlint/config-conventional @commitlint/cli

      - name: Create Commitlint Config
        run: |
          cat > commitlint.config.js << 'EOF'
          module.exports = {
            extends: ['@commitlint/config-conventional'],
            rules: {
              'type-enum': [2, 'always', [
                'build', 'chore', 'ci', 'docs', 'feat', 'fix',
                'perf', 'refactor', 'revert', 'style', 'test'
              ]],
              'subject-case': [2, 'never', ['start-case', 'pascal-case', 'upper-case']],
              'subject-max-length': [2, 'always', 100],
              'body-max-line-length': [2, 'always', 100],
              'footer-max-line-length': [2, 'always', 100]
            }
          }
          EOF

      - name: Check PR Title
        id: check_title
        env:
          PR_TITLE: ${{ github.event.pull_request.title }}
        run: |
          echo "Checking PR title: $PR_TITLE"
          if echo "$PR_TITLE" | npx commitlint; then
            echo "title_valid=true" >> "$GITHUB_OUTPUT"
          else
            echo "title_valid=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Check PR Commits
        id: check_commits
        run: |
          COMMITS=$(git rev-list --reverse ${{ github.event.pull_request.base.sha }}..${{ github.event.pull_request.head.sha }})
          COMMIT_COUNT=$(echo "$COMMITS" | wc -l)
          VALID=0
          INVALID=""

          for commit in $COMMITS; do
            MSG=$(git log --format=%B -n 1 "$commit" | head -n 1)
            if echo "$MSG" | npx commitlint 2>/dev/null; then
              VALID=$((VALID + 1))
            else
              INVALID="$INVALID\n- \`${commit:0:7}\`: $MSG"
            fi
          done

          echo "commit_count=$COMMIT_COUNT" >> "$GITHUB_OUTPUT"
          echo "valid_commits=$VALID" >> "$GITHUB_OUTPUT"

          if [ "$VALID" -eq "$COMMIT_COUNT" ]; then
            echo "commits_valid=true" >> "$GITHUB_OUTPUT"
          else
            echo "commits_valid=false" >> "$GITHUB_OUTPUT"
            {
              echo "invalid_commits<<EOF"
              echo -e "$INVALID"
              echo "EOF"
            } >> "$GITHUB_OUTPUT"
          fi

      - name: Update PR comment
        if: always()
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          # Pass values via env (data, not code) so special chars like
          # backticks in commit messages are never evaluated by the shell.
          TITLE_VALID: ${{ steps.check_title.outputs.title_valid }}
          COMMITS_VALID: ${{ steps.check_commits.outputs.commits_valid }}
          COMMIT_COUNT: ${{ steps.check_commits.outputs.commit_count }}
          INVALID_COMMITS: ${{ steps.check_commits.outputs.invalid_commits }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          REPO: ${{ github.repository }}
        run: |
          BODY="## Conventional Commits Validation\n\n"

          if [ "$TITLE_VALID" = "true" ]; then
            BODY="${BODY}**PR Title**: valid\n"
          else
            BODY="${BODY}**PR Title**: invalid — please use \`type(scope): description\`\n"
          fi

          if [ "$COMMITS_VALID" = "true" ]; then
            BODY="${BODY}**Commits**: all ${COMMIT_COUNT} follow conventional format\n"
          else
            BODY="${BODY}**Commits**: some do not follow conventional format\n"
            BODY="${BODY}${INVALID_COMMITS}\n"
          fi

          if [ "$TITLE_VALID" != "true" ] || \
             [ "$COMMITS_VALID" != "true" ]; then
            BODY="${BODY}\n### Format\n\n\`type(scope): description\`\n\n"
            BODY="${BODY}**Types**: \`feat\`, \`fix\`, \`docs\`, \`style\`, \`refactor\`, \`test\`, \`chore\`, \`ci\`, \`build\`, \`perf\`, \`revert\`\n"
          fi

          COMMENT_ID=$(gh pr view "$PR_NUMBER" --json comments \
            --jq '.comments[] | select(.author.login == "github-actions[bot]" and (.body | test("Conventional Commits Validation"))) | .id' \
            | head -n 1)

          if [ -n "$COMMENT_ID" ]; then
            gh api -X PATCH "repos/${REPO}/issues/comments/$COMMENT_ID" \
              -f body="$(echo -e "$BODY")"
          else
            gh pr comment "$PR_NUMBER" --body "$(echo -e "$BODY")"
          fi

      - name: Set commit status
        if: always()
        run: |
          SHA="${{ github.event.pull_request.head.sha }}"

          title_state="success"
          title_desc="PR title follows conventional commits"
          if [ "${{ steps.check_title.outputs.title_valid }}" != "true" ]; then
            title_state="failure"
            title_desc="PR title does not follow conventional commits"
          fi

          commits_state="success"
          commits_desc="All commits follow conventional commits"
          if [ "${{ steps.check_commits.outputs.commits_valid }}" != "true" ]; then
            commits_state="failure"
            commits_desc="Some commits do not follow conventional commits"
          fi

          gh api -X POST "repos/${{ github.repository }}/statuses/$SHA" \
            -f state="$title_state" \
            -f context="conventional-commits/title" \
            -f description="$title_desc"

          gh api -X POST "repos/${{ github.repository }}/statuses/$SHA" \
            -f state="$commits_state" \
            -f context="conventional-commits/commits" \
            -f description="$commits_desc"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Label PR
        uses: bcoe/conventional-release-labels@v1
        with:
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Final validation
        run: |
          if [ "${{ steps.check_title.outputs.title_valid }}" = "true" ] && \
             [ "${{ steps.check_commits.outputs.commits_valid }}" = "true" ]; then
            echo "All conventional commits validations passed"
          else
            echo "Conventional commits validation failed"
            exit 1
          fi