pr-edit.yml

# from https://github.com/LemLib/LemLib/blob/master/.github/workflows/pr-comment.yml
name: Add Template to Pull Request 
on:
  workflow_run:
    workflows: ['Build']
    types: [completed]
  workflow_dispatch:
jobs:
  pr_comment:
    # if build was successful and ran on a branch that is currently the head in a pull request
    if: github.event.workflow_run.conclusion == 'success'
    runs-on: ubuntu-latest

    permissions: 
      pull-requests: write
    
    steps:
      - uses: actions/github-script@v6
        with:
          # This snippet is public-domain, taken from
          # https://github.com/oprypin/nightly.link/blob/master/.github/workflows/pr-comment.yml
          script: |
            async function upsertComment(owner, repo, issue_number, purpose,old_body, body) {
              const {data: comments} = await github.rest.issues.listComments(
                {owner, repo, issue_number});
                
              const marker = `\r\n<!-- DO NOT REMOVE!! -->\r\n<!-- bot: ${purpose} -->\r\n`;

              const old_marker = new RegExp(marker.replace("\r\n", "\r?\n")).exec(old_body)?.[0] ?? marker;
              
              body = old_body.split(old_marker)[0] + marker + body;
              await github.request('PATCH /repos/{owner}/{repo}/pulls/{pull_number}', {
                owner: owner,
                repo: repo,
                pull_number: issue_number,
                body: body,
                headers: {
                  'X-GitHub-Api-Version': '2022-11-28'
                }
              }) 
            }
            
            const {owner, repo} = context.repo;
            const run_id = ${{github.event.workflow_run.id}};
            
            const pull_head_sha = '${{github.event.workflow_run.head_sha}}';
            
            /** @type {{old_body: string}} */
            const {issue_number, old_body} = await (async () => {
              const pulls = await github.rest.pulls.list({owner, repo});
              for await (const {data} of github.paginate.iterator(pulls)) {
                for (const pull of data) {
                  if (pull.head.sha === pull_head_sha) {
                    return {issue_number: pull.number, old_body: pull.body};
                  }
                }
              }
              return {};  
            })();            
            if (issue_number) {
              core.info(`Using pull request ${issue_number}`);
            } else {
              return core.error(`No matching pull request found`);
            }
            
            let old_sha = /\<\!-- commit-sha: (?<sha>[a-z0-9]+) --\>/i.exec(old_body)?.groups?.sha
            if (old_sha != undefined && pull_head_sha == old_sha) return core.error("Comment is already up-to-date!")
            
            const artifacts = await github.paginate(
              github.rest.actions.listWorkflowRunArtifacts, {owner, repo, run_id});
            if (!artifacts.length) {
              return core.error(`No artifacts found, perhaps Build Template was skipped`);
            }
            const template = artifacts[0];
            
            let body = `<!-- commit-sha: ${pull_head_sha} -->\n`;
            body +=`## Download the template for this pull request: \n\n`;
            body += `> [!NOTE]  
            > This is auto generated from [\`${{ github.workflow }}\`](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }})\n`;  
            body += `- via manual download: [${template.name}.zip](https://nightly.link/${owner}/${repo}/actions/artifacts/${template.id}.zip)\n`;
            body += `- via PROS Integrated Terminal: \n \`\`\`
            curl -o ${template.name}.zip https://nightly.link/${owner}/${repo}/actions/artifacts/${template.id}.zip;
            pros c fetch ${template.name}.zip;
            pros c apply ${template.name};
            rm ${template.name}.zip;
            \`\`\``;
            
            core.info(`Review thread message body: \n${body}`);
            
            await upsertComment(owner, repo, issue_number,
              "nightly-link", old_body, body);