Issue #3130751 by stefanos.petrakis, Medha Kumari, larowlan, alexpott, jungle:...

   * {@inheritdoc}

   */

  public function getLangcode(Request $request = NULL) {

    if ($request === NULL || $this->languageManager === NULL) {

      return NULL;

    }

    $langcode = $request->query->get(static::QUERY_PARAMETER);

    $language_enabled = array_key_exists($langcode, $this->languageManager->getLanguages());

<?php

namespace Drupal\Tests\language\Unit\Plugin\LanguageNegotiation;

use Symfony\Component\HttpFoundation\Request;

use Drupal\Core\Cache\Context\CacheContextsManager;

use Drupal\Core\DependencyInjection\ContainerBuilder;

use Drupal\Core\Entity\EntityTypeManager;

use Drupal\Core\Language\LanguageInterface;

use Drupal\Core\Session\AccountInterface;

use Drupal\language\ConfigurableLanguageManagerInterface;

use Drupal\Tests\UnitTestCase;

use Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationContentEntity;

/**

 * Tests the LanguageNegotiationContentEntity plugin class.

 *

 * @group language

 * @coversDefaultClass \Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationContentEntity

 * @see \Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationContentEntity

 */

class LanguageNegotiationContentEntityTest extends UnitTestCase {

  /**

   * An array of mock LanguageInterface objects.

   *

   * @var \Drupal\Core\Language\LanguageInterface

   */

  protected array $languages;

  /**

   * A mock LanguageManager object.

   *

   * @var \Drupal\language\ConfigurableLanguageManagerInterface

   */

  protected $languageManager;

  /**

   * A mock object implementing the AccountInterface.

   *

   * @var \Drupal\Core\Session\AccountInterface

   */

  protected $user;

  /**

   * {@inheritdoc}

   */

  protected function setUp(): void {

    // Set up some languages to be used by the language-based path processor.

    $language_de = $this->createMock(LanguageInterface::class);

    $language_de->expects($this->any())

      ->method('getId')

      ->will($this->returnValue('de'));

    $language_en = $this->createMock(LanguageInterface::class);

    $language_en->expects($this->any())

      ->method('getId')

      ->will($this->returnValue('en'));

    $languages = [

      'de' => $language_de,

      'en' => $language_en,

    ];

    $this->languages = $languages;

    $language_manager = $this->getMockBuilder(ConfigurableLanguageManagerInterface::class)

      ->getMock();

    $language_manager->expects($this->any())

      ->method('getLanguages')

      ->will($this->returnValue($languages));

    $this->languageManager = $language_manager;

    $this->user = $this->getMockBuilder(AccountInterface::class)

      ->getMock();

    $cache_contexts_manager = $this->getMockBuilder(CacheContextsManager::class)

      ->disableOriginalConstructor()

      ->getMock();

    $cache_contexts_manager->method('assertValidTokens')->willReturn(TRUE);

    $container = new ContainerBuilder();

    $container->set('cache_contexts_manager', $cache_contexts_manager);

    \Drupal::setContainer($container);

  }

  /**

   * @covers ::getLangcode

   */

  public function testGetLangcode() {

    $entityTypeManagerMock = $this->getMockBuilder(EntityTypeManager::class)

      ->disableOriginalConstructor()

      ->getMock();

    $languageNegotiationContentEntity = new LanguageNegotiationContentEntity($entityTypeManagerMock);

    $languageNegotiationContentEntity->setLanguageManager($this->languageManager);

    // Case 1: NULL request object argument.

    $this->assertSame(NULL, $languageNegotiationContentEntity->getLangcode());

    // Case 2: A request object is available, but the languageManager is not

    // set.

    $request = Request::create('/foo', 'GET');

    $this->assertSame(NULL, $languageNegotiationContentEntity->getLangcode($request));

    // Case 3: A request object is available, but static::QUERY_PARAMETER is

    // set to a non-enabled language.

    $request = Request::create('/foo', 'GET',

      [LanguageNegotiationContentEntity::QUERY_PARAMETER => 'it']);

    $this->assertSame(NULL, $languageNegotiationContentEntity->getLangcode($request));

    // Case 4: A request object is available and static::QUERY_PARAMETER is

    // set to an enabled language.

    $request = Request::create('/foo', 'GET',

      [LanguageNegotiationContentEntity::QUERY_PARAMETER => 'de']);

    $this->assertSame('de', $languageNegotiationContentEntity->getLangcode($request));

  }

}