prevent_multiple_pr.yml

name: Close Issue if Opener has Opened Pull Requests

on:
  pull_request_target:
    types:
      - opened

jobs:
  close_pull_request:
    runs-on: ubuntu-latest

    steps:
      - name: Check if opener has multiple open pull requests
        id: check_open_pull_requests
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
          script: |
            const owner = context.repo.owner;
            const repo = context.repo.repo;
            const pullRequestNumber = context.payload.pull_request.number;
            const pullRequestOpener = context.payload.pull_request.user.login;

            const previousPullRequestsResponse = await github.pulls.list({
              owner,
              repo,
              state: 'open'
            });

            const previousOpenPullRequests = previousPullRequestsResponse.data.filter(pr => pr.user.login === pullRequestOpener && pr.number !== pullRequestNumber);
            const previousOpenPullRequestNumbers = previousOpenPullRequests.map(pr => `#${pr.number}`);
            const openerName = context.payload.pull_request.user.login;

            const closePullRequest = previousOpenPullRequests.length > 0;
            console.log(`Close pull request: ${closePullRequest}`);

            if (closePullRequest) {
              const comment = `Hey @${openerName}, you can't open another pull request before completing the previous one 😀\nYou already have the following ${previousOpenPullRequests.length} open pull request(s):\n${previousOpenPullRequestNumbers.join('\n')}`;
              core.exportVariable('comment_body', comment);
              core.setOutput('close_pull_request', true);
            } else {
              core.exportVariable('comment_body', '');
              core.setOutput('close_pull_request', false);
              return; // Return and skip further steps
            }

      - name: Close the pull request and add a comment
        if: always() && ${{ needs.check_open_pull_requests.outputs.close_pull_request }}
        uses: actions/github-script@v4
        with:
          github-token: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
          script: |
            const owner = context.repo.owner;
            const repo = context.repo.repo;
            const pullRequestNumber = context.payload.pull_request.number;
            const comment = process.env.comment_body;

            if (comment.trim() === '') {
              console.log('Comment body is empty. Skipping comment creation.');
              return;
            }

            const closeComment = `${comment}`;

            await github.issues.createComment({
              owner,
              repo,
              issue_number: pullRequestNumber,
              body: closeComment
            });

            await github.pulls.update({
              owner,
              repo,
              pull_number: pullRequestNumber,
              state: 'closed'
            });