class CurrentThemeConditionTest

class CurrentThemeConditionTest extends KernelTestBase {
  
  /**
   * {@inheritdoc}
   */
  protected static $modules = [
    'system',
    'theme_test',
  ];
  
  /**
   * Tests the current theme condition.
   */
  public function testCurrentTheme() {
    \Drupal::service('theme_installer')->install([
      'test_theme',
    ]);
    $manager = \Drupal::service('plugin.manager.condition');
    /** @var \Drupal\Core\Condition\ConditionInterface $condition */
    $condition = $manager->createInstance('current_theme');
    $condition->setConfiguration([
      'theme' => 'test_theme',
    ]);
    /** @var \Drupal\Core\Condition\ConditionInterface $condition_negated */
    $condition_negated = $manager->createInstance('current_theme');
    $condition_negated->setConfiguration([
      'theme' => 'test_theme',
      'negate' => TRUE,
    ]);
    $this->assertEquals(new FormattableMarkup('The current theme is @theme', [
      '@theme' => 'test_theme',
    ]), $condition->summary());
    $this->assertEquals(new FormattableMarkup('The current theme is not @theme', [
      '@theme' => 'test_theme',
    ]), $condition_negated->summary());
    // The expected theme has not been set up yet.
    $this->assertFalse($condition->execute());
    $this->assertTrue($condition_negated->execute());
    // Set the expected theme to be used.
    $this->config('system.theme')
      ->set('default', 'test_theme')
      ->save();
    \Drupal::theme()->resetActiveTheme();
    $this->assertTrue($condition->execute());
    $this->assertFalse($condition_negated->execute());
  }

}