BlockAddTest.php

<?php

declare (strict_types=1);
namespace Drupal\Tests\block\FunctionalJavascript;

use Drupal\FunctionalJavascriptTests\WebDriverTestBase;

/**
 * Tests the JS functionality in the block add form.
 *
 * @group block
 */
class BlockAddTest extends WebDriverTestBase {

  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'block',
    'user',
  ];

  /**
   * {@inheritdoc}
   */
  protected $defaultTheme = 'stark';

  /**
   * Tests the AJAX for the theme selector.
   */
  public function testBlockAddThemeSelector() {
    \Drupal::service('theme_installer')
      ->install([
      'claro',
    ]);
    $this
      ->drupalLogin($this
      ->drupalCreateUser([
      'administer blocks',
    ]));
    $this
      ->drupalGet('admin/structure/block/add/system_powered_by_block');
    $assert_session = $this
      ->assertSession();

    // Pick a theme with a region that does not exist in another theme.
    $assert_session
      ->selectExists('Theme')
      ->selectOption('claro');
    $assert_session
      ->assertWaitOnAjaxRequest();
    $assert_session
      ->selectExists('Region')
      ->selectOption('pre_content');

    // Switch to a theme that doesn't contain the region selected above.
    $assert_session
      ->selectExists('Theme')
      ->selectOption('stark');
    $assert_session
      ->assertWaitOnAjaxRequest();
    $assert_session
      ->pageTextNotContains('The submitted value Pre-content in the Region element is not allowed.');
    $assert_session
      ->optionExists('Region', '- Select -');
  }

}