LanguageUILanguageNegotiationTest.php

<?php

namespace Drupal\Tests\language\Functional;

use Drupal\Component\Render\FormattableMarkup;
use Drupal\Core\Cache\Cache;
use Drupal\Core\Url;
use Drupal\file\Entity\File;
use Drupal\language\Entity\ConfigurableLanguage;
use Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationBrowser;
use Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationSelected;
use Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationSession;
use Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationUrl;
use Drupal\Tests\BrowserTestBase;
use Drupal\user\Plugin\LanguageNegotiation\LanguageNegotiationUser;
use Drupal\user\Plugin\LanguageNegotiation\LanguageNegotiationUserAdmin;
use Drupal\Core\Language\Language;
use Drupal\Core\Language\LanguageInterface;
use Symfony\Component\HttpFoundation\Request;
use Drupal\language\LanguageNegotiatorInterface;
use Drupal\block\Entity\Block;

/**
 * Tests the language UI for language switching.
 *
 * The uses cases that get tested, are:
 * - URL (path) > default: Test that the URL prefix setting gets precedence over
 *   the default language. The browser language preference does not have any
 *   influence.
 * - URL (path) > browser > default: Test that the URL prefix setting gets
 *   precedence over the browser language preference, which in turn gets
 *   precedence over the default language.
 * - URL (domain) > default: Tests that the URL domain setting gets precedence
 *   over the default language.
 *
 * The paths that are used for each of these, are:
 * - admin/config: Tests the UI using the precedence rules.
 * - zh-hans/admin/config: Tests the UI in Chinese.
 * - blah-blah/admin/config: Tests the 404 page.
 *
 * @group language
 */
class LanguageUILanguageNegotiationTest extends BrowserTestBase {
    
    /**
     * The admin user for testing.
     *
     * @var \Drupal\user\Entity\User
     */
    protected $adminUser;
    
    /**
     * Modules to enable.
     *
     * We marginally use interface translation functionality here, so need to use
     * the locale module instead of language only, but the 90% of the test is
     * about the negotiation process which is solely in language module.
     *
     * @var array
     */
    protected static $modules = [
        'locale',
        'language_test',
        'block',
        'user',
        'content_translation',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        $this->adminUser = $this->drupalCreateUser([
            'administer languages',
            'translate interface',
            'access administration pages',
            'administer blocks',
        ]);
        $this->drupalLogin($this->adminUser);
    }
    
    /**
     * Tests for language switching by URL path.
     */
    public function testUILanguageNegotiation() {
        // A few languages to switch to.
        // This one is unknown, should get the default lang version.
        $langcode_unknown = 'blah-blah';
        // For testing browser lang preference.
        $langcode_browser_fallback = 'vi';
        // For testing path prefix.
        $langcode = 'zh-hans';
        // For setting browser language preference to 'vi'.
        $http_header_browser_fallback = [
            "Accept-Language" => "{$langcode_browser_fallback};q=1",
        ];
        // For setting browser language preference to some unknown.
        $http_header_blah = [
            "Accept-Language" => "blah;q=1",
        ];
        // Create a private file for testing accessible by the admin user.
        \Drupal::service('file_system')->mkdir($this->privateFilesDirectory . '/test');
        $filepath = 'private://test/private-file-test.txt';
        $contents = "file_put_contents() doesn't seem to appreciate empty strings so let's put in some data.";
        file_put_contents($filepath, $contents);
        $file = File::create([
            'uri' => $filepath,
            'uid' => $this->adminUser
                ->id(),
        ]);
        $file->save();
        // Setup the site languages by installing two languages.
        // Set the default language in order for the translated string to be registered
        // into database when seen by t(). Without doing this, our target string
        // is for some reason not found when doing translate search. This might
        // be some bug.
        $default_language = \Drupal::languageManager()->getDefaultLanguage();
        ConfigurableLanguage::createFromLangcode($langcode_browser_fallback)->save();
        $this->config('system.site')
            ->set('default_langcode', $langcode_browser_fallback)
            ->save();
        ConfigurableLanguage::createFromLangcode($langcode)->save();
        // We will look for this string in the admin/config screen to see if the
        // corresponding translated string is shown.
        $default_string = 'Hide descriptions';
        // First visit this page to make sure our target string is searchable.
        $this->drupalGet('admin/config');
        // Now the t()'ed string is in db so switch the language back to default.
        // This will rebuild the container so we need to rebuild the container in
        // the test environment.
        $this->config('system.site')
            ->set('default_langcode', $default_language->getId())
            ->save();
        $this->config('language.negotiation')
            ->set('url.prefixes.en', '')
            ->save();
        $this->rebuildContainer();
        // Translate the string.
        $language_browser_fallback_string = "In {$langcode_browser_fallback} In {$langcode_browser_fallback} In {$langcode_browser_fallback}";
        $language_string = "In {$langcode} In {$langcode} In {$langcode}";
        // Do a translate search of our target string.
        $search = [
            'string' => $default_string,
            'langcode' => $langcode_browser_fallback,
        ];
        $this->drupalGet('admin/config/regional/translate');
        $this->submitForm($search, 'Filter');
        $textarea = $this->assertSession()
            ->elementExists('xpath', '//textarea');
        $lid = $textarea->getAttribute('name');
        $edit = [
            $lid => $language_browser_fallback_string,
        ];
        $this->drupalGet('admin/config/regional/translate');
        $this->submitForm($edit, 'Save translations');
        $search = [
            'string' => $default_string,
            'langcode' => $langcode,
        ];
        $this->drupalGet('admin/config/regional/translate');
        $this->submitForm($search, 'Filter');
        $textarea = $this->assertSession()
            ->elementExists('xpath', '//textarea');
        $lid = $textarea->getAttribute('name');
        $edit = [
            $lid => $language_string,
        ];
        $this->drupalGet('admin/config/regional/translate');
        $this->submitForm($edit, 'Save translations');
        // Configure selected language negotiation to use zh-hans.
        $edit = [
            'selected_langcode' => $langcode,
        ];
        $this->drupalGet('admin/config/regional/language/detection/selected');
        $this->submitForm($edit, 'Save configuration');
        $test = [
            'language_negotiation' => [
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $language_string,
            'expected_method_id' => LanguageNegotiationSelected::METHOD_ID,
            'http_header' => $http_header_browser_fallback,
            'message' => 'SELECTED: UI language is switched based on selected language.',
        ];
        $this->doRunTest($test);
        // An invalid language is selected.
        $this->config('language.negotiation')
            ->set('selected_langcode', NULL)
            ->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $default_string,
            'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
            'http_header' => $http_header_browser_fallback,
            'message' => 'SELECTED > DEFAULT: UI language is switched based on selected language.',
        ];
        $this->doRunTest($test);
        // No selected language is available.
        $this->config('language.negotiation')
            ->set('selected_langcode', $langcode_unknown)
            ->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $default_string,
            'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
            'http_header' => $http_header_browser_fallback,
            'message' => 'SELECTED > DEFAULT: UI language is switched based on selected language.',
        ];
        $this->doRunTest($test);
        $tests = [
            // Default, browser preference should have no influence.
[
                'language_negotiation' => [
                    LanguageNegotiationUrl::METHOD_ID,
                    LanguageNegotiationSelected::METHOD_ID,
                ],
                'path' => 'admin/config',
                'expect' => $default_string,
                'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
                'http_header' => $http_header_browser_fallback,
                'message' => 'URL (PATH) > DEFAULT: no language prefix, UI language is default and the browser language preference setting is not used.',
            ],
            // Language prefix.
[
                'language_negotiation' => [
                    LanguageNegotiationUrl::METHOD_ID,
                    LanguageNegotiationSelected::METHOD_ID,
                ],
                'path' => "{$langcode}/admin/config",
                'expect' => $language_string,
                'expected_method_id' => LanguageNegotiationUrl::METHOD_ID,
                'http_header' => $http_header_browser_fallback,
                'message' => 'URL (PATH) > DEFAULT: with language prefix, UI language is switched based on path prefix',
            ],
            // Default, go by browser preference.
[
                'language_negotiation' => [
                    LanguageNegotiationUrl::METHOD_ID,
                    LanguageNegotiationBrowser::METHOD_ID,
                ],
                'path' => 'admin/config',
                'expect' => $language_browser_fallback_string,
                'expected_method_id' => LanguageNegotiationBrowser::METHOD_ID,
                'http_header' => $http_header_browser_fallback,
                'message' => 'URL (PATH) > BROWSER: no language prefix, UI language is determined by browser language preference',
            ],
            // Prefix, switch to the language.
[
                'language_negotiation' => [
                    LanguageNegotiationUrl::METHOD_ID,
                    LanguageNegotiationBrowser::METHOD_ID,
                ],
                'path' => "{$langcode}/admin/config",
                'expect' => $language_string,
                'expected_method_id' => LanguageNegotiationUrl::METHOD_ID,
                'http_header' => $http_header_browser_fallback,
                'message' => 'URL (PATH) > BROWSER: with language prefix, UI language is based on path prefix',
            ],
            // Default, browser language preference is not one of site's lang.
[
                'language_negotiation' => [
                    LanguageNegotiationUrl::METHOD_ID,
                    LanguageNegotiationBrowser::METHOD_ID,
                    LanguageNegotiationSelected::METHOD_ID,
                ],
                'path' => 'admin/config',
                'expect' => $default_string,
                'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
                'http_header' => $http_header_blah,
                'message' => 'URL (PATH) > BROWSER > DEFAULT: no language prefix and browser language preference set to unknown language should use default language',
            ],
        ];
        foreach ($tests as $test) {
            $this->doRunTest($test);
        }
        // Unknown language prefix should return 404.
        $definitions = \Drupal::languageManager()->getNegotiator()
            ->getNegotiationMethods();
        // Enable only methods, which are either not limited to a specific language
        // type or are supporting the interface language type.
        $language_interface_method_definitions = array_filter($definitions, function ($method_definition) {
            return !isset($method_definition['types']) || isset($method_definition['types']) && in_array(LanguageInterface::TYPE_INTERFACE, $method_definition['types']);
        });
        $this->config('language.types')
            ->set('negotiation.' . LanguageInterface::TYPE_INTERFACE . '.enabled', array_flip(array_keys($language_interface_method_definitions)))
            ->save();
        $this->drupalGet("{$langcode_unknown}/admin/config", [], $http_header_browser_fallback);
        $this->assertSession()
            ->statusCodeEquals(404);
        // Set preferred langcode for user to NULL.
        $account = $this->loggedInUser;
        $account->preferred_langcode = NULL;
        $account->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationUser::METHOD_ID,
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $default_string,
            'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
            'http_header' => [],
            'message' => 'USER > DEFAULT: no preferred user language setting, the UI language is default',
        ];
        $this->doRunTest($test);
        // Set preferred langcode for user to default langcode.
        $account = $this->loggedInUser;
        $account->preferred_langcode = $default_language->getId();
        $account->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationUser::METHOD_ID,
                LanguageNegotiationUrl::METHOD_ID,
            ],
            'path' => "{$langcode}/admin/config",
            'expect' => $default_string,
            'expected_method_id' => LanguageNegotiationUser::METHOD_ID,
            'http_header' => [],
            'message' => 'USER > URL: User has default language as preferred user language setting, the UI language is default',
        ];
        $this->doRunTest($test);
        // Set preferred langcode for user to unknown language.
        $account = $this->loggedInUser;
        $account->preferred_langcode = $langcode_unknown;
        $account->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationUser::METHOD_ID,
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $default_string,
            'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
            'http_header' => [],
            'message' => 'USER > DEFAULT: invalid preferred user language setting, the UI language is default',
        ];
        $this->doRunTest($test);
        // Set preferred langcode for user to non default.
        $account->preferred_langcode = $langcode;
        $account->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationUser::METHOD_ID,
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $language_string,
            'expected_method_id' => LanguageNegotiationUser::METHOD_ID,
            'http_header' => [],
            'message' => 'USER > DEFAULT: defined preferred user language setting, the UI language is based on user setting',
        ];
        $this->doRunTest($test);
        // Set preferred admin langcode for user to NULL.
        $account->preferred_admin_langcode = NULL;
        $account->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationUserAdmin::METHOD_ID,
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $default_string,
            'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
            'http_header' => [],
            'message' => 'USER ADMIN > DEFAULT: no preferred user admin language setting, the UI language is default',
        ];
        $this->doRunTest($test);
        // Set preferred admin langcode for user to unknown language.
        $account->preferred_admin_langcode = $langcode_unknown;
        $account->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationUserAdmin::METHOD_ID,
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $default_string,
            'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
            'http_header' => [],
            'message' => 'USER ADMIN > DEFAULT: invalid preferred user admin language setting, the UI language is default',
        ];
        $this->doRunTest($test);
        // Set preferred admin langcode for user to non default.
        $account->preferred_admin_langcode = $langcode;
        $account->save();
        $test = [
            'language_negotiation' => [
                LanguageNegotiationUserAdmin::METHOD_ID,
                LanguageNegotiationSelected::METHOD_ID,
            ],
            'path' => 'admin/config',
            'expect' => $language_string,
            'expected_method_id' => LanguageNegotiationUserAdmin::METHOD_ID,
            'http_header' => [],
            'message' => 'USER ADMIN > DEFAULT: defined preferred user admin language setting, the UI language is based on user setting',
        ];
        $this->doRunTest($test);
        // Go by session preference.
        $language_negotiation_session_param = $this->randomMachineName();
        $edit = [
            'language_negotiation_session_param' => $language_negotiation_session_param,
        ];
        $this->drupalGet('admin/config/regional/language/detection/session');
        $this->submitForm($edit, 'Save configuration');
        $tests = [
            [
                'language_negotiation' => [
                    LanguageNegotiationSession::METHOD_ID,
                ],
                'path' => "admin/config",
                'expect' => $default_string,
                'expected_method_id' => LanguageNegotiatorInterface::METHOD_ID,
                'http_header' => $http_header_browser_fallback,
                'message' => 'SESSION > DEFAULT: no language given, the UI language is default',
            ],
            [
                'language_negotiation' => [
                    LanguageNegotiationSession::METHOD_ID,
                ],
                'path' => 'admin/config',
                'path_options' => [
                    'query' => [
                        $language_negotiation_session_param => $langcode,
                    ],
                ],
                'expect' => $language_string,
                'expected_method_id' => LanguageNegotiationSession::METHOD_ID,
                'http_header' => $http_header_browser_fallback,
                'message' => 'SESSION > DEFAULT: language given, UI language is determined by session language preference',
            ],
        ];
        foreach ($tests as $test) {
            $this->doRunTest($test);
        }
    }
    protected function doRunTest($test) {
        $test += [
            'path_options' => [],
        ];
        if (!empty($test['language_negotiation'])) {
            $method_weights = array_flip($test['language_negotiation']);
            $this->container
                ->get('language_negotiator')
                ->saveConfiguration(LanguageInterface::TYPE_INTERFACE, $method_weights);
        }
        if (!empty($test['language_negotiation_url_part'])) {
            $this->config('language.negotiation')
                ->set('url.source', $test['language_negotiation_url_part'])
                ->save();
        }
        if (!empty($test['language_test_domain'])) {
            \Drupal::state()->set('language_test.domain', $test['language_test_domain']);
        }
        $this->container
            ->get('language_manager')
            ->reset();
        $this->drupalGet($test['path'], $test['path_options'], $test['http_header']);
        $this->assertSession()
            ->pageTextContains($test['expect']);
        $this->assertSession()
            ->statusMessageContains('Language negotiation method: ' . $test['expected_method_id'], 'status');
        // Get the private file and ensure it is a 200. It is important to
        // invalidate the router cache to ensure the routing system runs a full
        // match.
        Cache::invalidateTags([
            'route_match',
        ]);
        $this->drupalGet('system/files/test/private-file-test.txt');
        $this->assertSession()
            ->statusCodeEquals(200);
    }
    
    /**
     * Tests URL language detection when the requested URL has no language.
     */
    public function testUrlLanguageFallback() {
        // Add the Italian language.
        $langcode_browser_fallback = 'it';
        ConfigurableLanguage::createFromLangcode($langcode_browser_fallback)->save();
        $languages = $this->container
            ->get('language_manager')
            ->getLanguages();
        // Enable the path prefix for the default language: this way any unprefixed
        // URL must have a valid fallback value.
        $edit = [
            'prefix[en]' => 'en',
        ];
        $this->drupalGet('admin/config/regional/language/detection/url');
        $this->submitForm($edit, 'Save configuration');
        // Enable browser and URL language detection.
        $edit = [
            'language_interface[enabled][language-browser]' => TRUE,
            'language_interface[enabled][language-url]' => TRUE,
            'language_interface[weight][language-browser]' => -8,
            'language_interface[weight][language-url]' => -10,
        ];
        $this->drupalGet('admin/config/regional/language/detection');
        $this->submitForm($edit, 'Save settings');
        $this->drupalGet('admin/config/regional/language/detection');
        // Enable the language switcher block.
        $this->drupalPlaceBlock('language_block:' . LanguageInterface::TYPE_INTERFACE, [
            'id' => 'test_language_block',
        ]);
        // Log out, because for anonymous users, the "active" class is set by PHP
        // (which means we can easily test it here), whereas for authenticated users
        // it is set by JavaScript.
        $this->drupalLogout();
        // Place a site branding block in the header region.
        $this->drupalPlaceBlock('system_branding_block', [
            'region' => 'header',
            'id' => 'site-branding',
        ]);
        // Access the front page without specifying any valid URL language prefix
        // and having as browser language preference a non-default language.
        $http_header = [
            "Accept-Language" => "{$langcode_browser_fallback};q=1",
        ];
        $language = new Language([
            'id' => '',
        ]);
        $this->drupalGet('', [
            'language' => $language,
        ], $http_header);
        // Check that the language switcher active link matches the given browser
        // language.
        $href = Url::fromRoute('<front>')->toString() . $langcode_browser_fallback;
        $this->assertSession()
            ->elementTextEquals('xpath', "//div[@id='block-test-language-block']//a[@class='language-link is-active' and starts-with(@href, '{$href}')]", $languages[$langcode_browser_fallback]->getName());
        // Check that URLs are rewritten using the given browser language.
        $this->assertSession()
            ->elementTextEquals('xpath', "//div[@id='block-site-branding']/a[@rel='home' and @href='{$href}'][2]", 'Drupal');
    }
    
    /**
     * Tests URL handling when separate domains are used for multiple languages.
     */
    public function testLanguageDomain() {
        global $base_url;
        // Get the current host URI we're running on.
        $base_url_host = parse_url($base_url, PHP_URL_HOST);
        // Add the Italian language.
        ConfigurableLanguage::createFromLangcode('it')->save();
        $languages = $this->container
            ->get('language_manager')
            ->getLanguages();
        // Enable browser and URL language detection.
        $edit = [
            'language_interface[enabled][language-url]' => TRUE,
            'language_interface[weight][language-url]' => -10,
        ];
        $this->drupalGet('admin/config/regional/language/detection');
        $this->submitForm($edit, 'Save settings');
        // Do not allow blank domain.
        $edit = [
            'language_negotiation_url_part' => LanguageNegotiationUrl::CONFIG_DOMAIN,
            'domain[en]' => '',
        ];
        $this->drupalGet('admin/config/regional/language/detection/url');
        $this->submitForm($edit, 'Save configuration');
        $this->assertSession()
            ->statusMessageContains('The domain may not be left blank for English', 'error');
        $this->rebuildContainer();
        // Change the domain for the Italian language.
        $edit = [
            'language_negotiation_url_part' => LanguageNegotiationUrl::CONFIG_DOMAIN,
            'domain[en]' => $base_url_host,
            'domain[it]' => 'it.example.com',
        ];
        $this->drupalGet('admin/config/regional/language/detection/url');
        $this->submitForm($edit, 'Save configuration');
        $this->assertSession()
            ->statusMessageContains('The configuration options have been saved', 'status');
        $this->rebuildContainer();
        // Try to use an invalid domain.
        $edit = [
            'language_negotiation_url_part' => LanguageNegotiationUrl::CONFIG_DOMAIN,
            'domain[en]' => $base_url_host,
            'domain[it]' => 'it.example.com/',
        ];
        $this->drupalGet('admin/config/regional/language/detection/url');
        $this->submitForm($edit, 'Save configuration');
        $this->assertSession()
            ->statusMessageContains("The domain for Italian may only contain the domain name, not a trailing slash, protocol and/or port.", 'error');
        // Build the link we're going to test.
        $link = 'it.example.com' . rtrim(base_path(), '/') . '/admin';
        // Test URL in another language: http://it.example.com/admin.
        // Base path gives problems on the testbot, so $correct_link is hard-coded.
        // @see UrlAlterFunctionalTest::assertUrlOutboundAlter (path.test).
        $italian_url = Url::fromRoute('system.admin', [], [
            'language' => $languages['it'],
        ])->toString();
        $url_scheme = \Drupal::request()->isSecure() ? 'https://' : 'http://';
        $correct_link = $url_scheme . $link;
        $this->assertEquals($correct_link, $italian_url, new FormattableMarkup('The right URL (@url) in accordance with the chosen language', [
            '@url' => $italian_url,
        ]));
        // Test HTTPS via options.
        $italian_url = Url::fromRoute('system.admin', [], [
            'https' => TRUE,
            'language' => $languages['it'],
        ])->toString();
        $correct_link = 'https://' . $link;
        $this->assertSame($correct_link, $italian_url, new FormattableMarkup('The right HTTPS URL (via options) (@url) in accordance with the chosen language', [
            '@url' => $italian_url,
        ]));
        // Test HTTPS via current URL scheme.
        $request = Request::create('', 'GET', [], [], [], [
            'HTTPS' => 'on',
        ]);
        $this->container
            ->get('request_stack')
            ->push($request);
        $italian_url = Url::fromRoute('system.admin', [], [
            'language' => $languages['it'],
        ])->toString();
        $correct_link = 'https://' . $link;
        $this->assertSame($correct_link, $italian_url, new FormattableMarkup('The right URL (via current URL scheme) (@url) in accordance with the chosen language', [
            '@url' => $italian_url,
        ]));
    }
    
    /**
     * Tests persistence of negotiation settings for the content language type.
     */
    public function testContentCustomization() {
        // Customize content language settings from their defaults.
        $edit = [
            'language_content[configurable]' => TRUE,
            'language_content[enabled][language-url]' => FALSE,
            'language_content[enabled][language-session]' => TRUE,
        ];
        $this->drupalGet('admin/config/regional/language/detection');
        $this->submitForm($edit, 'Save settings');
        // Check if configurability persisted.
        $config = $this->config('language.types');
        $this->assertContains('language_interface', $config->get('configurable'), 'Interface language is configurable.');
        $this->assertContains('language_content', $config->get('configurable'), 'Content language is configurable.');
        // Ensure configuration was saved.
        $this->assertArrayNotHasKey('language-url', $config->get('negotiation.language_content.enabled'));
        $this->assertArrayHasKey('language-session', $config->get('negotiation.language_content.enabled'));
    }
    
    /**
     * Tests if the language switcher block gets deleted when a language type has been made not configurable.
     */
    public function testDisableLanguageSwitcher() {
        $block_id = 'test_language_block';
        // Enable the language switcher block.
        $this->drupalPlaceBlock('language_block:' . LanguageInterface::TYPE_CONTENT, [
            'id' => $block_id,
        ]);
        // Check if the language switcher block has been created.
        $block = Block::load($block_id);
        $this->assertNotEmpty($block, 'Language switcher block was created.');
        // Make sure language_content is not configurable.
        $edit = [
            'language_content[configurable]' => FALSE,
        ];
        $this->drupalGet('admin/config/regional/language/detection');
        $this->submitForm($edit, 'Save settings');
        $this->assertSession()
            ->statusCodeEquals(200);
        // Check if the language switcher block has been removed.
        $block = Block::load($block_id);
        $this->assertNull($block, 'Language switcher block was removed.');
    }

}