Issue #2893029 by phenaproxima, Sam152, tim.plunkett, dawehner, a.dmitriiev,...

Issue #2893029 by phenaproxima, Sam152, tim.plunkett, dawehner, a.dmitriiev, Berdir: StringTranslationTrait consumers cannot be reliably serialized without DependencySerializationTrait

core/lib/Drupal/Core/Entity/EntityType.php

@@ -3,6 +3,7 @@
 namespace Drupal\Core\Entity;
 
 use Drupal\Component\Plugin\Definition\PluginDefinition;
+use Drupal\Core\DependencyInjection\DependencySerializationTrait;
 use Drupal\Core\Entity\Exception\EntityTypeIdLengthException;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
@@ -14,6 +15,7 @@
  */
 class EntityType extends PluginDefinition implements EntityTypeInterface {
 
+  use DependencySerializationTrait;
   use StringTranslationTrait;
 
   /**

core/tests/Drupal/Tests/Core/Entity/EntityTypeTest.php

@@ -5,6 +5,7 @@
 use Drupal\Core\Entity\EntityType;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\StringTranslation\TranslationInterface;
 use Drupal\Tests\UnitTestCase;
 
 /**
@@ -476,4 +477,22 @@ protected function assertNoPublicProperties(EntityTypeInterface $entity_type) {
     $this->assertEmpty($reflection->getProperties(\ReflectionProperty::IS_PUBLIC));
   }
 
+  /**
+   * Test the EntityType object it serializable.
+   */
+  public function testIsSerializable() {
+    $entity_type = $this->setUpEntityType([]);
+
+    $translation = $this->prophesize(TranslationInterface::class);
+    $translation->willImplement(\Serializable::class);
+    $translation->serialize()->willThrow(\Exception::class);
+    $translation_service = $translation->reveal();
+    $translation_service->_serviceId = 'string_translation';
+
+    $entity_type->setStringTranslation($translation_service);
+    $entity_type = unserialize(serialize($entity_type));
+
+    $this->assertEquals('example_entity_type', $entity_type->id());
+  }
+
 }