class BlockContentThemeSuggestionsTestHooks

class BlockContentThemeSuggestionsTestHooks {
    use StringTranslationTrait;
    
    /**
     * Implements hook_entity_extra_field_info().
     */
    public function entityExtraFieldInfo() : array {
        // Add an extra field to the test bundle.
        $extra['node']['bundle_with_extra_field']['display']['block_content_extra_field_test'] = [
            'label' => $this->t('Extra field'),
            'description' => $this->t('Extra field description'),
            'weight' => 0,
        ];
        return $extra;
    }
    
    /**
     * Implements hook_node_view().
     */
    public function nodeView(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display, string $view_mode) : void {
        // Provide content for the extra field in the form of a content block.
        if ($display->getComponent('block_content_extra_field_test')) {
            $entity_type_manager = \Drupal::entityTypeManager();
            // Load a block content entity with a known UUID created by test setup.
            // @see \Drupal\Tests\block_content\Functional\BlockContentThemeSuggestionsTest::setUp()
            $block_content = $entity_type_manager->getStorage('block_content')
                ->loadByProperties([
                'uuid' => 'b22c881a-bcfd-4d0c-a41d-3573327705df',
            ]);
            $block_content = reset($block_content);
            $build['block_content_extra_field_test'] = $entity_type_manager->getViewBuilder('block_content')
                ->view($block_content);
        }
    }
    
    /**
     * Implements hook_theme().
     */
    public function theme() : array {
        // It is necessary to explicitly register the template via hook_theme()
        // because it is added via a module, not a theme.
        return [
            'block__block_content__view_type__basic__full' => [
                'base hook' => 'block',
            ],
        ];
    }

}