github-script/.github/workflows/pull-request-test.yml

name: Pull Request Test

on:
  pull_request:
    branches: main
    types: [opened, synchronize]

jobs:
  pull-request-test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: ./
        with:
          script: |
            // Get the existing comments.
            const {data: comments} = await github.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.payload.number,
            })

            // Find any comment already made by the bot.                                                                                                    
            const botComment = comments.find(comment => comment.user.id === 41898282)                                                                       
            const commentBody = "Hello from actions/github-script! (${{ github.sha }})"                  

            if (context.payload.pull_request.head.repo.full_name !== 'actions/github-script') {
              console.log('Not attempting to write comment on PR from fork');
            } else {
              if (botComment) {
                await github.issues.updateComment({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  comment_id: botComment.id,
                  body: commentBody
                })
              } else {
                await github.issues.createComment({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  issue_number: context.payload.number,
                  body: commentBody
                })
              }
            }