#3530149: Add tests from private issue for SA-CORE-2025-004.

Closes #3530149

core/modules/link/tests/src/Kernel/LinkFormatterTest.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\link\Kernel;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
+use Drupal\user\Entity\Role;
+use Drupal\user\RoleInterface;
+
+/**
+ * Tests the Field Formatter for the link field type.
+ *
+ * @group link
+ */
+class LinkFormatterTest extends EntityKernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  protected static $modules = ['link'];
+
+  /**
+   * The entity type used in this test.
+   *
+   * @var string
+   */
+  protected string $entityType = 'entity_test';
+
+  /**
+   * The bundle used in this test.
+   *
+   * @var string
+   */
+  protected string $bundle = 'entity_test';
+
+  /**
+   * The name of the field used in this test.
+   *
+   * @var string
+   */
+  protected string $fieldName = 'field_test';
+
+  /**
+   * The entity to be tested.
+   *
+   * @var \Drupal\Core\Entity\EntityInterface
+   */
+  protected $entity;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Use Stark theme for testing markup output.
+    \Drupal::service('theme_installer')->install(['stark']);
+    $this->config('system.theme')->set('default', 'stark')->save();
+    $this->installEntitySchema('entity_test');
+    // Grant the 'view test entity' permission.
+    $this->installConfig(['user']);
+    Role::load(RoleInterface::ANONYMOUS_ID)
+      ->grantPermission('view test entity')
+      ->save();
+
+    FieldStorageConfig::create([
+      'field_name' => $this->fieldName,
+      'type' => 'link',
+      'entity_type' => $this->entityType,
+      'cardinality' => 1,
+    ])->save();
+
+    FieldConfig::create([
+      'field_name' => $this->fieldName,
+      'entity_type' => $this->entityType,
+      'bundle' => $this->bundle,
+      'label' => 'Field test',
+    ])->save();
+  }
+
+  /**
+   * Tests the link formatters.
+   *
+   * @param string $formatter
+   *   The name of the link formatter to test.
+   *
+   * @dataProvider providerLinkFormatter
+   */
+  public function testLinkFormatter(string $formatter): void {
+    $entity = $this->container->get('entity_type.manager')
+      ->getStorage($this->entityType)
+      ->create([
+        'name' => $this->randomMachineName(),
+        $this->fieldName => [
+          'uri' => 'https://www.drupal.org/',
+          'title' => 'Hello world',
+          'options' => [
+            'attributes' => [
+              'class' => 'classy',
+              'onmouseover' => 'alert(document.cookie)',
+            ],
+          ],
+        ],
+      ]);
+    $entity->save();
+
+    $build = $entity->get($this->fieldName)->view(['type' => $formatter]);
+
+    $renderer = $this->container->get('renderer');
+    $renderer->renderRoot($build[0]);
+
+    $output = (string) $build[0]['#markup'];
+    $this->assertStringContainsString('<a href="https://www.drupal.org/" class="classy">', $output);
+    $this->assertStringNotContainsString('onmouseover=', $output);
+  }
+
+  /**
+   * Data provider for ::testLinkFormatter.
+   */
+  public static function providerLinkFormatter(): array {
+    return [
+      'default formatter' => ['link'],
+      'separate link text and URL' => ['link_separate'],
+    ];
+  }
+
+}