check_pr_description.yml

name: Check PR description
on:
  pull_request:
    types:
      - opened
      - reopened
permissions: read-all
jobs:
  check_pr_description:
    permissions:
      pull-requests: write
    runs-on: ubuntu-latest
    steps:
      - name: Setup Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '16'
      - name: Run PR description check
        uses: actions/github-script@v6
        with:
          script: |
            const pr = context.payload.pull_request;
            const prDescription = pr.body;

            if (!prDescription) {
              core.setFailed("The PR description is missing or does not meet the required format.");
            }

            const requiredSections = [
                '## Overview',
                '## Essential Checklist',
                '## Proof that changes are correct',
                '## PR Pointers'
            ];

            const missingSections = requiredSections.filter(
                section => !prDescription.includes(section)
            );

            if (missingSections.length > 0) {
                const username = pr.user.login;
                const comment = `Hi @${username}, it looks like the description of this PR doesn't use our [template](https://github.com/oppia/oppia/blob/develop/.github/PULL_REQUEST_TEMPLATE.md), which is pre-populated when you open a new PR. Specifically, it's missing the following required sections:\n\n` + missingSections.map(s => `- ${s.replace(/^##\s*/, '')}`).join('\n') + `Please re-open this PR and fill in the template without deleting any required sections.`
                await github.rest.issues.createComment({
                    owner: context.repo.owner,
                    repo: context.repo.repo,
                    issue_number: pr.number,
                    body: comment
                });

                await github.rest.pulls.update({
                    owner: context.repo.owner,
                    repo: context.repo.repo,
                    pull_number: pr.number,
                    state: 'closed'
                });

                core.setFailed("The PR description is missing required sections.");
            }