class EntityTestUpdateHooks

class EntityTestUpdateHooks {
    
    /**
     * Implements hook_entity_base_field_info().
     */
    public function entityBaseFieldInfo(EntityTypeInterface $entity_type) {
        // Add a base field that will be used to test that fields added through
        // hook_entity_base_field_info() are handled correctly during a schema
        // conversion (e.g. from non-revisionable to revisionable).
        if ($entity_type->id() == 'entity_test_update') {
            $fields = [];
            $fields['test_entity_base_field_info'] = BaseFieldDefinition::create('string')->setLabel(new TranslatableMarkup('Field added by hook_entity_base_field_info()'))
                ->setTranslatable(TRUE)
                ->setRevisionable(TRUE);
            return $fields;
        }
    }
    
    /**
     * Implements hook_entity_field_storage_info().
     */
    public function entityFieldStorageInfo(EntityTypeInterface $entity_type) {
        if ($entity_type->id() == 'entity_test_update') {
            return \Drupal::state()->get('entity_test_update.additional_field_storage_definitions', []);
        }
    }
    
    /**
     * Implements hook_entity_type_alter().
     */
    public function entityTypeAlter(array &$entity_types) : void {
        // Allow entity_test_update tests to override the entity type definition.
        $entity_type = \Drupal::state()->get('entity_test_update.entity_type', $entity_types['entity_test_update']);
        if ($entity_type !== 'null') {
            $entity_types['entity_test_update'] = $entity_type;
        }
        else {
            unset($entity_types['entity_test_update']);
        }
    }
    
    /**
     * Implements hook_ENTITY_TYPE_presave() for the 'view' entity type.
     */
    public function viewPresave(EntityInterface $entity) {
        if (\Drupal::state()->get('entity_test_update.throw_view_exception') === $entity->id()) {
            throw new \LogicException('The view could not be saved.');
        }
    }

}