coreutils/.github/workflows/GnuComment.yml

name: GnuComment

on:
  workflow_run:
    workflows: ["GnuTests"]
    types:
      - completed

permissions: {}
jobs:
  post-comment:
    permissions:
      actions: read  #  to list workflow runs artifacts
      pull-requests: write  #  to comment on pr

    runs-on: ubuntu-latest
    if: >
      github.event.workflow_run.event == 'pull_request'      
    steps:
      - name: 'Download artifact'
        uses: actions/github-script@v6
        with:
          script: |
            // List all artifacts from GnuTests
            var artifacts = await github.rest.actions.listWorkflowRunArtifacts({
              owner: context.repo.owner,
              repo: context.repo.repo,
              run_id: ${{ github.event.workflow_run.id }},
            });

            // Download the "comment" artifact, which contains a PR number (NR) and result.txt
            var matchArtifact = artifacts.data.artifacts.filter((artifact) => {
              return artifact.name == "comment"
            })[0];
            var download = await github.rest.actions.downloadArtifact({
              owner: context.repo.owner,
              repo: context.repo.repo,
              artifact_id: matchArtifact.id,
              archive_format: 'zip',
            });
            var fs = require('fs');
            fs.writeFileSync('${{ github.workspace }}/comment.zip', Buffer.from(download.data));            
      - run: unzip comment.zip

      - name: 'Comment on PR'
        uses: actions/github-script@v6
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            var fs = require('fs');
            var issue_number = Number(fs.readFileSync('./NR'));
            var content = fs.readFileSync('./result.txt');
            if (content.toString().trim().length > 7) { // 7 because we have backquote + \n
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: issue_number,
                body: 'GNU testsuite comparison:\n```\n' + content + '```'
              });
            }