Issue #2938803 by David_Rothstein, spitzialist, vsujeetkumar, yepa, harsha012,...

    ];

    foreach (array_keys($names) as $profile_name) {

      $form['profile'][$profile_name]['#description'] = isset($profiles[$profile_name]['description']) ? $this->t($profiles[$profile_name]['description']) : '';

      // @todo Remove hardcoding of 'demo_umami' profile for a generic warning

      // system in https://www.drupal.org/project/drupal/issues/2822414.

      if ($profile_name === 'demo_umami') {

        $this->addUmamiWarning($form);

      }

    }

    $config_sync_directory = Settings::get('config_sync_directory');

    $install_state['parameters']['profile'] = $profile;

  }

  /**

   * Show profile warning if 'demo_umami' profile is selected.

   */

  protected function addUmamiWarning(array &$form) {

    // Warning to show when this profile is selected.

    $description = $form['profile']['demo_umami']['#description'];

    // Re-defines radio #description to show warning when selected.

    $form['profile']['demo_umami']['#description'] = [

      'warning' => [

        '#type' => 'item',

        '#markup' => $this->t('This profile is intended for demonstration purposes only.'),

        '#wrapper_attributes' => [

          'class' => ['messages', 'messages--warning'],

        ],

        '#states' => [

          'visible' => [

            ':input[name="profile"]' => ['value' => 'demo_umami'],

          ],

        ],

      ],

      'description' => ['#markup' => $description],

    ];

  }

}

<?php

namespace Drupal\FunctionalJavascriptTests\Core\Installer\Form;

use Drupal\Core\DependencyInjection\ContainerBuilder;

use Drupal\Core\Language\Language;

use Drupal\Core\Session\UserSession;

use Drupal\Core\Test\HttpClientMiddleware\TestHttpClientMiddleware;

use Drupal\FunctionalJavascriptTests\WebDriverTestBase;

use GuzzleHttp\HandlerStack;

use Symfony\Component\DependencyInjection\Reference;

use Symfony\Component\HttpFoundation\Request;

use Symfony\Component\HttpFoundation\RequestStack;

/**

 * Tests the select profile form.

 *

 * @group Installer

 */

class SelectProfileFormTest extends WebDriverTestBase {

  /**

   * {@inheritdoc}

   */

  public function setUp(): void {

    $this->setupBaseUrl();

    $this->prepareDatabasePrefix();

    // Install Drupal test site.

    $this->prepareEnvironment();

    // Define information about the user 1 account.

    $this->rootUser = new UserSession([

      'uid' => 1,

      'name' => 'admin',

      'mail' => 'admin@example.com',

      'pass_raw' => $this->randomMachineName(),

    ]);

    // Create a regular settings.php for testing.

    $this->prepareSettings();

    // @todo Using the APCu file cache causes problems in this test when

    //   combined with Symfony 4.4. This seems to be a memory issue caused by

    //   excessive deprecation errors caused by

    //   https://github.com/symfony/symfony/commit/7c01c4c80c69159b2b39ea8bc53431196d7b29fb

    //   The deprecations will be fixed in https://www.drupal.org/project/drupal/issues/3074585

    $settings['settings']['file_cache']['file_cache_disable'] = (object) [

      'value' => TRUE,

      'required' => TRUE,

    ];

    $this->writeSettings($settings);

    // Note that FunctionalTestSetupTrait::installParameters() returns form

    // input values suitable for a programmed

    // \Drupal::formBuilder()->submitForm().

    // @see InstallerTestBase::translatePostValues()

    $this->parameters = $this->installParameters();

    // Set up a minimal container (required by BrowserTestBase). Set cookie and

    // server information so that XDebug works.

    // @see install_begin_request()

    $request = Request::create($GLOBALS['base_url'] . '/core/install.php', 'GET', [], $_COOKIE, [], $_SERVER);

    $this->container = new ContainerBuilder();

    $request_stack = new RequestStack();

    $request_stack->push($request);

    $this->container

      ->set('request_stack', $request_stack);

    $this->container

      ->setParameter('language.default_values', Language::$defaultValues);

    $this->container

      ->register('language.default', 'Drupal\Core\Language\LanguageDefault')

      ->addArgument('%language.default_values%');

    $this->container

      ->register('string_translation', 'Drupal\Core\StringTranslation\TranslationManager')

      ->addArgument(new Reference('language.default'));

    $this->container

      ->register('http_client', 'GuzzleHttp\Client')

      ->setFactory('http_client_factory:fromOptions');

    $this->container

      ->register('http_client_factory', 'Drupal\Core\Http\ClientFactory')

      ->setArguments([new Reference('http_handler_stack')]);

    $handler_stack = HandlerStack::create();

    $test_http_client_middleware = new TestHttpClientMiddleware();

    $handler_stack->push($test_http_client_middleware(), 'test.http_client.middleware');

    $this->container

      ->set('http_handler_stack', $handler_stack);

    $this->container

      ->setParameter('app.root', DRUPAL_ROOT);

    \Drupal::setContainer($this->container);

    // Setup Mink.

    $this->initMink();

  }

  /**

   * {@inheritdoc}

   */

  protected function initMink() {

    // The temporary files directory doesn't exist yet, as install_base_system()

    // has not run. We need to create the template cache directory recursively.

    $path = $this->tempFilesDirectory . DIRECTORY_SEPARATOR . 'browsertestbase-templatecache';

    if (!file_exists($path)) {

      mkdir($path, 0777, TRUE);

    }

    parent::initMink();

  }

  /**

   * {@inheritdoc}

   *

   * BrowserTestBase::refreshVariables() tries to operate on persistent storage,

   * which is only available after the installer completed.

   */

  protected function refreshVariables() {

    // Intentionally empty as the site is not yet installed.

  }

  /**

   * Tests a warning message is displayed when the Umami profile is selected.

   */

  public function testUmamiProfileWarningMessage() {

    $this->drupalGet($GLOBALS['base_url'] . '/core/install.php');

    $edit = [

      'langcode' => 'en',

    ];

    $this->submitForm($edit, 'Save and continue');

    $page = $this->getSession()->getPage();

    $warning_message = $page->find('css', '.description .messages--warning');

    $this->assertFalse($warning_message->isVisible());

    $page->selectFieldOption('profile', 'demo_umami');

    $this->assertTrue($warning_message->isVisible());

  }

}