trait CommentTestTrait

trait CommentTestTrait {
    
    /**
     * Adds the default comment field to an entity.
     *
     * Attaches a comment field named 'comment' to the given entity type and
     * bundle. Largely replicates the default behavior in Drupal 7 and earlier.
     *
     * @param string $entity_type
     *   The entity type to attach the default comment field to.
     * @param string $bundle
     *   The bundle to attach the default comment field to.
     * @param string $field_name
     *   (optional) Field name to use for the comment field. Defaults to
     *     'comment'.
     * @param int $default_value
     *   (optional) Default value, one of CommentItemInterface::HIDDEN,
     *   CommentItemInterface::OPEN, CommentItemInterface::CLOSED. Defaults to
     *   CommentItemInterface::OPEN.
     * @param string $comment_type_id
     *   (optional) ID of comment type to use. Defaults to 'comment'.
     * @param string $comment_view_mode
     *   (optional) The comment view mode to be used in comment field formatter.
     *   Defaults to 'full'.
     */
    public function addDefaultCommentField($entity_type, $bundle, $field_name = 'comment', $default_value = CommentItemInterface::OPEN, $comment_type_id = 'comment', $comment_view_mode = 'full') {
        $entity_type_manager = \Drupal::entityTypeManager();
        $entity_display_repository = \Drupal::service('entity_display.repository');
        
        /** @var \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager */
        $entity_field_manager = \Drupal::service('entity_field.manager');
        // Create the comment type if needed.
        $comment_type_storage = $entity_type_manager->getStorage('comment_type');
        if ($comment_type = $comment_type_storage->load($comment_type_id)) {
            if ($comment_type->getTargetEntityTypeId() !== $entity_type) {
                throw new \InvalidArgumentException("The given comment type id {$comment_type_id} can only be used with the {$entity_type} entity type");
            }
        }
        else {
            $comment_type_storage->create([
                'id' => $comment_type_id,
                'label' => Unicode::ucfirst($comment_type_id),
                'target_entity_type_id' => $entity_type,
                'description' => 'Default comment field',
            ])
                ->save();
        }
        // Add a body field to the comment type.
        \Drupal::service('comment.manager')->addBodyField($comment_type_id);
        // Add a comment field to the host entity type. Create the field storage if
        // needed.
        if (!array_key_exists($field_name, $entity_field_manager->getFieldStorageDefinitions($entity_type))) {
            $entity_type_manager->getStorage('field_storage_config')
                ->create([
                'entity_type' => $entity_type,
                'field_name' => $field_name,
                'type' => 'comment',
                'translatable' => TRUE,
                'settings' => [
                    'comment_type' => $comment_type_id,
                ],
            ])
                ->save();
        }
        // Create the field if needed, and configure its form and view displays.
        if (!array_key_exists($field_name, $entity_field_manager->getFieldDefinitions($entity_type, $bundle))) {
            $entity_type_manager->getStorage('field_config')
                ->create([
                'label' => 'Comments',
                'description' => '',
                'field_name' => $field_name,
                'entity_type' => $entity_type,
                'bundle' => $bundle,
                'required' => 1,
                'default_value' => [
                    [
                        'status' => $default_value,
                        'cid' => 0,
                        'last_comment_name' => '',
                        'last_comment_timestamp' => 0,
                        'last_comment_uid' => 0,
                    ],
                ],
            ])
                ->save();
            // Entity form displays: assign widget settings for the default form
            // mode, and hide the field in all other form modes.
            $entity_display_repository->getFormDisplay($entity_type, $bundle)
                ->setComponent($field_name, [
                'type' => 'comment_default',
                'weight' => 20,
            ])
                ->save();
            foreach ($entity_display_repository->getFormModes($entity_type) as $id => $form_mode) {
                $display = $entity_display_repository->getFormDisplay($entity_type, $bundle, $id);
                // Only update existing displays.
                if ($display && !$display->isNew()) {
                    $display->removeComponent($field_name)
                        ->save();
                }
            }
            // Entity view displays: assign widget settings for the default view
            // mode, and hide the field in all other view modes.
            $entity_display_repository->getViewDisplay($entity_type, $bundle)
                ->setComponent($field_name, [
                'label' => 'above',
                'type' => 'comment_default',
                'weight' => 20,
                'settings' => [
                    'view_mode' => $comment_view_mode,
                ],
            ])
                ->save();
            foreach ($entity_display_repository->getViewModes($entity_type) as $id => $view_mode) {
                $display = $entity_display_repository->getViewDisplay($entity_type, $bundle, $id);
                // Only update existing displays.
                if ($display && !$display->isNew()) {
                    $display->removeComponent($field_name)
                        ->save();
                }
            }
        }
    }

}