commit-check-workflow-b.yml

# Workflow B: Post PR comment after commit checks complete.
#
# This workflow is triggered by the workflow_run event from Workflow A.
# It runs in the base repository's context with full write permissions,
# making it safe for fork PRs (no checkout of fork code).
#
# Prerequisites:
#   - Workflow A (commit-check.yml) must exist and upload an artifact named
#     commit-check-result-<PR-number> containing result.txt
#
# See https://github.com/commit-check/commit-check-action#fork-pr-comments

name: Commit Check Comment

on:
  workflow_run:
    workflows: ["Commit Check"]  # must match Workflow A's name exactly
    types: [completed]

jobs:
  comment:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
      actions: read  # needed to download artifacts
    steps:
      - uses: actions/download-artifact@v4
        with:
          name: commit-check-result-${{ github.event.workflow_run.pull_requests[0].number }}
          run-id: ${{ github.event.workflow_run.id }}
          github-token: ${{ github.token }}

      - name: Read result and post PR comment
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const prNumber = ${{ github.event.workflow_run.pull_requests[0].number }};
            const resultText = fs.readFileSync('result.txt', 'utf8').trim();

            const successTitle = '# Commit-Check ✔️';
            const failureTitle = '# Commit-Check ❌';
            const body = resultText
              ? `${failureTitle}\n\`\`\`\n${resultText}\n\`\`\``
              : successTitle;

            const { data: comments } = await github.rest.issues.listComments({
              ...context.repo,
              issue_number: prNumber,
            });

            const existing = comments.find(c =>
              c.body.startsWith(successTitle) || c.body.startsWith(failureTitle)
            );

            if (existing) {
              await github.rest.issues.updateComment({
                ...context.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                ...context.repo,
                issue_number: prNumber,
                body,
              });
            }