Issue #3077287 by gabesullice: Followup to #2819335:...

    // Merge the entity's cacheability metadata with that of the normalization

    // parts, so that RenderCache can take care of cache redirects for us.

    CacheableMetadata::createFromObject($object)

      ->merge(static::mergeCacheableDependencies($normalization_parts[static::RESOURCE_CACHE_SUBSET_BASE]))

      ->merge(static::mergeCacheableDependencies($normalization_parts[static::RESOURCE_CACHE_SUBSET_FIELDS]))

      ->applyTo($data_as_render_array);

<?php

namespace Drupal\Tests\jsonapi\Kernel\EventSubscriber;

use Drupal\Core\Cache\Cache;

use Drupal\Core\Cache\CacheableMetadata;

use Drupal\jsonapi\EventSubscriber\ResourceObjectNormalizationCacher;

use Drupal\jsonapi\JsonApiResource\ResourceObject;

use Drupal\jsonapi\Normalizer\Value\CacheableNormalization;

use Drupal\KernelTests\KernelTestBase;

use Drupal\user\Entity\User;

use Symfony\Component\HttpKernel\Event\PostResponseEvent;

/**

 * @coversDefaultClass \Drupal\jsonapi\EventSubscriber\ResourceObjectNormalizationCacher

 * @group jsonapi

 *

 * @internal

 */

class ResourceObjectNormalizerCacherTest extends KernelTestBase {

  /**

   * {@inheritdoc}

   */

  protected static $modules = [

    'serialization',

    'jsonapi',

    'user',

  ];

  /**

   * The JSON:API resource type repository.

   *

   * @var \Drupal\jsonapi\ResourceType\ResourceTypeRepositoryInterface

   */

  protected $resourceTypeRepository;

  /**

   * The JSON:API serializer.

   *

   * @var \Drupal\jsonapi\Serializer\Serializer

   */

  protected $serializer;

  /**

   * The object under test.

   *

   * @var \Drupal\jsonapi\EventSubscriber\ResourceObjectNormalizationCacher

   */

  protected $cacher;

  /**

   * {@inheritdoc}

   */

  protected function setUp() {

    parent::setUp();

    $this->resourceTypeRepository = $this->container->get('jsonapi.resource_type.repository');

    $this->serializer = $this->container->get('jsonapi.serializer');

    $this->cacher = $this->container->get('jsonapi.normalization_cacher');

  }

  /**

   * Tests that link normalization cache information is not lost.

   *

   * @see https://www.drupal.org/project/drupal/issues/3077287

   */

  public function testLinkNormalizationCacheability() {

    $user = User::create([

      'name' => $this->randomMachineName(),

      'pass' => $this->randomString(),

    ]);

    $resource_type = $this->resourceTypeRepository->get($user->getEntityTypeId(), $user->bundle());

    $resource_object = ResourceObject::createFromEntity($resource_type, $user);

    $cache_tag_to_invalidate = 'link_normalization';

    $normalized_links = $this->serializer

      ->normalize($resource_object->getLinks(), 'api_json')

      ->withCacheableDependency((new CacheableMetadata())->addCacheTags([$cache_tag_to_invalidate]));

    assert($normalized_links instanceof CacheableNormalization);

    $normalization_parts = [

      ResourceObjectNormalizationCacher::RESOURCE_CACHE_SUBSET_BASE => [

        'type' => CacheableNormalization::permanent($resource_object->getTypeName()),

        'id' => CacheableNormalization::permanent($resource_object->getId()),

        'links' => $normalized_links,

      ],

      ResourceObjectNormalizationCacher::RESOURCE_CACHE_SUBSET_FIELDS => [],

    ];

    $this->cacher->saveOnTerminate($resource_object, $normalization_parts);

    $event = $this->prophesize(PostResponseEvent::class);

    $this->cacher->onTerminate($event->reveal());

    $this->assertNotFalse((bool) $this->cacher->get($resource_object));

    Cache::invalidateTags([$cache_tag_to_invalidate]);

    $this->assertFalse((bool) $this->cacher->get($resource_object));

  }

}