action.yml

---
name: PRune
description: Replace PR descriptions with before/after SHA and changed files

runs:
  using: composite
  steps:
    - name: Write description
      uses: actions/github-script@v7
      with:
        script: |
          const pr = context.payload.pull_request;
          const short = sha => sha.slice(0, 7);
          const compareUrl = `${context.payload.repository.html_url}/compare/${pr.base.sha}...${pr.head.sha}`;

          const files = await github.paginate(github.rest.pulls.listFiles, {
            owner: context.repo.owner,
            repo: context.repo.repo,
            pull_number: pr.number,
            per_page: 100,
          });

          const changedFiles = files
            .slice(0, 20)
            .map(file => `- \`${file.filename}\` ${file.status} (+${file.additions}/-${file.deletions})`);
          if (files.length > 20) {
            changedFiles.push(`- ${files.length - 20} more files`);
          }

          const newBody = [
            '## Before',
            `\`${pr.base.ref}\` at \`${short(pr.base.sha)}\``,
            '',
            '## After',
            `\`${pr.head.ref}\` at \`${short(pr.head.sha)}\``,
            '',
            '## Changed',
            changedFiles.length ? changedFiles.join('\n') : '- No file changes reported',
            '',
            '## Compare',
            compareUrl,
            '',
            '---',
            '<img src="https://raw.githubusercontent.com/libnudget/bot/main/assets/avatar.png" width="16" alt=""> `libnudget/prune@v1`',
          ].join('\n');

          await github.rest.pulls.update({
            owner: context.repo.owner,
            repo: context.repo.repo,
            pull_number: pr.number,
            body: newBody,
          });

          core.info('PR #' + pr.number + ' description updated');