Issue #2142997 by stefan.r: Test for ValidReferenceConstraintValidator

core/modules/system/src/Tests/Entity/ValidReferenceConstraintValidatorTest.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Tests\Entity\ValidReferenceConstraintValidatorTest.
+ */
+
+namespace Drupal\system\Tests\Entity;
+
+use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\system\Tests\TypedData;
+
+/**
+ * Tests validation constraints for ValidReferenceConstraintValidator.
+ *
+ * @group Validation
+ */
+class ValidReferenceConstraintValidatorTest extends EntityUnitTestBase {
+
+  /**
+   * The typed data manager to use.
+   *
+   * @var \Drupal\Core\TypedData\TypedDataManager
+   */
+  protected $typedData;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = array('field', 'user');
+
+  /**
+   * @inheritdoc
+   */
+  public function setUp() {
+    parent::setUp();
+    $this->installSchema('user', array('users_data'));
+    $this->typedData = $this->container->get('typed_data_manager');
+  }
+
+  /**
+   * Tests the ValidReferenceConstraintValidator.
+   */
+  public function testValidation() {
+    // Create a test entity to be referenced.
+    $entity = $this->createUser();
+    // By default entity references already have the ValidReference constraint.
+    $definition = BaseFieldDefinition::create('entity_reference')
+      ->setSettings(array('target_type' => 'user'));
+
+    $typed_data = $this->typedData->create($definition, array('target_id' => $entity->id()));
+    $violations = $typed_data->validate();
+    $this->assertFalse($violations->count(), 'Validation passed for correct value.');
+
+    // NULL is also considered a valid reference.
+    $typed_data = $this->typedData->create($definition, array('target_id' => NULL));
+    $violations = $typed_data->validate();
+    $this->assertFalse($violations->count(), 'Validation passed for correct value.');
+
+    $typed_data = $this->typedData->create($definition, array('target_id' => $entity->id()));
+    // Delete the referenced entity.
+    $entity->delete();
+    $violations = $typed_data->validate();
+    $this->assertTrue($violations->count(), 'Validation failed for incorrect value.');
+
+    // Make sure the information provided by a violation is correct.
+    $violation = $violations[0];
+    $this->assertEqual($violation->getMessage(), t('The referenced entity (%type: %id) does not exist.', array(
+      '%type' => 'user',
+      '%id' => $entity->id(),
+    )), 'The message for invalid value is correct.');
+    $this->assertEqual($violation->getRoot(), $typed_data, 'Violation root is correct.');
+  }
+
+}