preview.yml

name: Manual Expo Preview

on:
  issue_comment:
    types: [created]

permissions:
  contents: read
  pull-requests: write
  issues: write

jobs:
  check_permissions:
    runs-on: ubuntu-latest
    if: github.event_name == 'issue_comment' && contains(github.event.comment.body, '/preview') && github.event.issue.pull_request
    outputs:
      has_permissions: ${{ steps.check.outputs.has_permissions }}
      pr_number: ${{ steps.get_pr_details.outputs.pr_number }}
      pr_head_ref: ${{ steps.get_pr_details.outputs.pr_head_ref }}
    steps:
      - name: Get PR details
        id: get_pr_details
        uses: actions/github-script@v7
        with:
          github-token: ${{secrets.GITHUB_TOKEN}}
          script: |
            const { data: pullRequest } = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: context.issue.number
            });
            core.setOutput('pr_number', pullRequest.number);
            core.setOutput('pr_head_ref', pullRequest.head.ref);

      - name: Check permissions
        id: check
        uses: actions/github-script@v7
        with:
          github-token: ${{secrets.GITHUB_TOKEN}}
          script: |
            const { data: permission } = await github.rest.repos.getCollaboratorPermissionLevel({
              owner: context.repo.owner,
              repo: context.repo.repo,
              username: context.payload.comment.user.login
            });
            const hasPermissions = ['admin', 'write'].includes(permission.permission);
            core.setOutput('has_permissions', hasPermissions);

  preview:
    needs: check_permissions
    if: needs.check_permissions.outputs.has_permissions == 'true'
    runs-on: ubuntu-latest
    steps:
      - name: Get PR details
        uses: actions/github-script@v7
        id: pr-details
        with:
          github-token: ${{secrets.GITHUB_TOKEN}}
          script: |
            const { data: pr } = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: ${{ needs.check_permissions.outputs.pr_number }}
            });
            core.setOutput('head_sha', pr.head.sha);
            core.setOutput('head_repo', pr.head.repo.full_name);
            core.setOutput('head_ref', pr.head.ref);

      - uses: actions/checkout@v4
        with:
          repository: ${{ steps.pr-details.outputs.head_repo }}
          ref: ${{ steps.pr-details.outputs.head_ref }}
          fetch-depth: 0

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Install dependencies
        run: npm install

      - name: Setup Expo
        uses: expo/expo-github-action@v8
        with:
          eas-version: latest
          eas-cache: true
          expo-version: latest
          expo-cache: true
          packager: npm
          token: ${{ secrets.EXPO_TOKEN }}

      - name: Create preview
        id: preview
        uses: expo/expo-github-action/preview@v8
        with:
          comment: false
          qr-target: 'expo-go'
          github-token: ${{ secrets.GITHUB_TOKEN }}
          command: eas update --auto --branch pr-${{ needs.check_permissions.outputs.pr_head_ref }}

      - name: Find Comment
        uses: peter-evans/find-comment@v3
        id: find_comment
        with:
          issue-number: ${{ needs.check_permissions.outputs.pr_number }}
          comment-author: 'github-actions[bot]'
          body-includes: Expo Preview

      - name: Create or Update Comment
        uses: peter-evans/create-or-update-comment@v4
        with:
          issue-number: ${{ needs.check_permissions.outputs.pr_number }}
          comment-id: ${{ steps.find_comment.outputs.comment-id }}
          body: |
            ## Expo Preview
            ${{steps.preview.outputs.comment}}
            > Commit hash: ${{steps.preview.outputs.gitCommitHash}}
            > Update published at: ${{steps.preview.outputs.createdAt}}
          edit-mode: replace

  pr_comment:
    needs: check_permissions
    if: needs.check_permissions.outputs.has_permissions != 'true'
    runs-on: ubuntu-latest
    steps:
      - name: Comment on PR (insufficient permissions)
        uses: peter-evans/create-or-update-comment@v4
        with:
          issue-number: ${{ needs.check_permissions.outputs.pr_number }}
          body: |
            Sorry, you do not have the required permissions to trigger an Expo preview. 
            Please ask a maintainer to review and trigger the preview if necessary.