add-preview-domain.yml

name: Assign preview-domain
on:
  # Trigger when a pull request is opened or reopened
  pull_request:
    types: [opened, reopened, ready_for_review, synchronize]

permissions:
  contents: read

jobs:
  assign-preview-domain:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - name: Prepare domain
        id: prepare
        uses: actions/github-script@v7.0.1
        with:
          script: |
            const subdomain = `${{ github.head_ref }}`
              .slice(0, 32)
              // Remove any trailing non-alphanumeric characters
              .replace(/[^a-zA-Z0-9](?=[^a-zA-Z0-9]*$)/, '')

            const domain = `${subdomain}.${{ vars.PREVIEW_DOMAIN }}`
              .toLowerCase()
              .replaceAll("_","-")
            core.setOutput('domain', domain)

      - name: Comment with the assigned preview-domain
        uses: actions/github-script@v7.0.1
        with:
          script: |
            const knownString = '### Preview domain'
            const pullRequest = await github.rest.pulls.get({
              pull_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
            })
            const hasAlreadyCommented = pullRequest.data.body ? pullRequest.data.body.includes(knownString) : false

            if (hasAlreadyCommented) {
              console.log('Already commented once')
            } else {
              console.log('Creating comment for the first time')
              const body = pullRequest.data.body
                ? `${pullRequest.data.body}\n\n${knownString}\nhttps://${{ steps.prepare.outputs.domain }}`
                : `${knownString}\nhttps://${{ steps.prepare.outputs.domain }}`

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

      - name: Assign preview-domain
        run: |
          curl -sX POST "https://vercel.com/api/v10/projects/${{ secrets.VERCEL_PROJECT_ID }}/domains?teamId=${{ secrets.VERCEL_TEAM_ID }}" \
            -H "Authorization: Bearer ${{ secrets.VERCEL_BEARER_TOKEN }}" \
            -H "Content-Type: application/json" \
            -d '{"name": "${{ steps.prepare.outputs.domain }}","gitBranch":"${{ github.head_ref }}"}'