class ComponentKernelTestBase

abstract class ComponentKernelTestBase extends KernelTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'system',
        'user',
        'serialization',
    ];
    
    /**
     * Themes to install.
     *
     * @var string[]
     */
    protected static $themes = [];
    
    /**
     * The component negotiator.
     *
     * @return \Drupal\Core\Theme\ComponentNegotiator
     */
    protected ComponentNegotiator $negotiator;
    
    /**
     * The component plugin manager.
     *
     * @var \Drupal\Core\Theme\ComponentPluginManager
     */
    protected ComponentPluginManager $manager;
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        if (empty(static::$themes)) {
            throw new \Exception('You need to set the protected static $themes property on your test class, with the first item being the default theme.');
        }
        $this->container
            ->get('theme_installer')
            ->install(static::$themes);
        $this->installConfig('system');
        $system_theme_config = $this->container
            ->get('config.factory')
            ->getEditable('system.theme');
        $theme_name = reset(static::$themes);
        $system_theme_config->set('default', $theme_name)
            ->save();
        $theme_manager = \Drupal::service('theme.manager');
        $active_theme = \Drupal::service('theme.initialization')->initTheme($theme_name);
        $theme_manager->setActiveTheme($active_theme);
        $this->negotiator = new ComponentNegotiator($theme_manager, \Drupal::service('extension.list.module'));
        $this->manager = \Drupal::service('plugin.manager.sdc');
    }
    
    /**
     * Renders a component for testing sake.
     *
     * @param array $component
     *   Component render array.
     * @param \Drupal\Core\Render\BubbleableMetadata|null $metadata
     *   Bubble metadata.
     *
     * @return \Symfony\Component\DomCrawler\Crawler
     *   Crawler for introspecting the rendered component.
     */
    protected function renderComponentRenderArray(array $component, ?BubbleableMetadata $metadata = NULL) : Crawler {
        $component = [
            '#type' => 'container',
            '#attributes' => [
                'id' => 'sdc-wrapper',
            ],
            'component' => $component,
        ];
        $metadata = $metadata ?: new BubbleableMetadata();
        $context = new RenderContext();
        $renderer = \Drupal::service('renderer');
        $output = $renderer->executeInRenderContext($context, fn() => $renderer->render($component));
        if (!$context->isEmpty()) {
            $metadata->addCacheableDependency($context->pop());
        }
        return new Crawler((string) $output);
    }

}