How do you set up a complete GitHub Actions CI pipeline for a Selenium Java project?

selenium-framework/
├── .github/
│   └── workflows/
│       ├── ci.yml           ← runs on every push/PR
│       └── nightly.yml      ← full regression at 2 AM
├── src/
│   └── test/java/...
├── testng.xml
├── smoke-testng.xml
└── pom.xml

# .github/workflows/ci.yml
name: Selenium Test Suite

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main, develop]
  workflow_dispatch:
    inputs:
      browser:
        type: choice
        options: [chrome, firefox, edge]
        default: chrome
      environment:
        type: choice
        options: [staging, qa]
        default: staging
      suite:
        type: choice
        options: [testng.xml, smoke-testng.xml]
        default: smoke-testng.xml

env:
  JAVA_VERSION:   '17'
  BROWSER:        ${{ inputs.browser || 'chrome' }}
  ENVIRONMENT:    ${{ inputs.environment || 'staging' }}
  SUITE:          ${{ inputs.suite || 'smoke-testng.xml' }}
  MAVEN_OPTS:     '-Xmx1024m'

jobs:
  selenium-tests:
    name: "${{ env.SUITE }} on ${{ env.BROWSER }} (${{ env.ENVIRONMENT }})"
    runs-on: ubuntu-latest

    steps:
      # 1. Get the code
      - name: Checkout repository
        uses: actions/checkout@v4

      # 2. Set up Java with Maven cache
      - name: Set up JDK ${{ env.JAVA_VERSION }}
        uses: actions/setup-java@v4
        with:
          java-version: ${{ env.JAVA_VERSION }}
          distribution: temurin
          cache: maven

      # 3. Install Chrome for headless execution
      - name: Install Google Chrome
        run: |
          sudo apt-get update -q
          sudo apt-get install -y google-chrome-stable
          google-chrome --version

      # 4. Run Selenium tests
      - name: Run Selenium Tests
        id: test-run
        run: |
          mvn test \
            -Dbrowser=${{ env.BROWSER }} \
            -Denv=${{ env.ENVIRONMENT }} \
            -Dsurefire.suiteXmlFiles=${{ env.SUITE }} \
            -Dheadless=true
        env:
          BASE_URL:    ${{ secrets.BASE_URL }}
          DB_USER:     ${{ secrets.DB_USER }}
          DB_PASSWORD: ${{ secrets.DB_PASSWORD }}
        continue-on-error: true

      # 5. Upload test reports (always)
      - name: Upload Surefire Reports
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: surefire-${{ env.BROWSER }}-${{ github.run_number }}
          path: target/surefire-reports/
          retention-days: 14

      - name: Upload Allure Results
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: allure-results-${{ github.run_number }}
          path: target/allure-results/
          retention-days: 14

      # 6. Upload screenshots on failure
      - name: Upload failure screenshots
        if: failure() || steps.test-run.outcome == 'failure'
        uses: actions/upload-artifact@v4
        with:
          name: screenshots-${{ github.run_number }}
          path: screenshots/
          if-no-files-found: ignore

      # 7. Notify Slack on failure
      - name: Slack notification on failure
        if: failure()
        uses: slackapi/slack-github-action@v1.26.0
        with:
          payload: |
            {
              "text": "❌ *Tests FAILED*: ${{ github.repository }} | Branch: ${{ github.ref_name }} | Browser: ${{ env.BROWSER }} | <${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
            }
        env:
          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}

      # 8. Fail the job if tests failed
      - name: Fail if tests failed
        if: steps.test-run.outcome == 'failure'
        run: exit 1

# .github/workflows/nightly.yml
name: Nightly Regression

on:
  schedule:
    - cron: '0 2 * * 1-5'   # 2 AM UTC weekdays

jobs:
  regression:
    strategy:
      fail-fast: false
      matrix:
        browser: [chrome, firefox]

    runs-on: ubuntu-latest
    name: Regression on ${{ matrix.browser }}

    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-java@v4
        with:
          java-version: '17'
          distribution: temurin
          cache: maven

      - run: sudo apt-get install -y google-chrome-stable firefox

      - name: Full regression
        run: mvn test -Dbrowser=${{ matrix.browser }} -Dsurefire.suiteXmlFiles=testng.xml
        env:
          BASE_URL: ${{ secrets.STAGING_URL }}

      - if: always()
        uses: actions/upload-artifact@v4
        with:
          name: nightly-${{ matrix.browser }}
          path: target/surefire-reports/

// Read from system property set by Maven
boolean headless = Boolean.parseBoolean(System.getProperty("headless", "false"));

ChromeOptions opts = new ChromeOptions();
if (headless) {
    opts.addArguments("--headless=new", "--no-sandbox",
                      "--disable-dev-shm-usage", "--window-size=1920,1080");
}
driver = new ChromeDriver(opts);