EntityTypeTest.php

<?php

namespace Drupal\KernelTests\Core\Entity;

use Drupal\Core\Entity\EntityType;
use Drupal\Core\StringTranslation\TranslationManager;
use Drupal\KernelTests\KernelTestBase;

/**
 * Tests general features of entity types.
 *
 * @group Entity
 */
class EntityTypeTest extends KernelTestBase {
    
    /**
     * Sets up an EntityType object for a given set of values.
     *
     * @param array $definition
     *   An array of values to use for the EntityType.
     *
     * @return \Drupal\Core\Entity\EntityTypeInterface
     */
    protected function setUpEntityType($definition) {
        $definition += [
            'id' => 'example_entity_type',
        ];
        return new EntityType($definition);
    }
    
    /**
     * Tests that the EntityType object can be serialized.
     */
    public function testIsSerializable() {
        $entity_type = $this->setUpEntityType([]);
        $translation_service = new class  extends TranslationManager {
            
            /**
             * Constructs a UnserializableTranslationManager object.
             */
            public function __construct() {
            }
            
            /**
             * Always throw an exception.
             */
            public function __serialize() : array {
                throw new \Exception();
            }

};
        $this->container
            ->set('bar', $translation_service);
        $entity_type->setStringTranslation($this->container
            ->get('string_translation'));
        // This should not throw an exception.
        $tmp = serialize($entity_type);
        $entity_type = unserialize($tmp);
        // And this should have the correct id.
        $this->assertEquals('example_entity_type', $entity_type->id());
    }

}