--- /dev/null
+<?php
+
+namespace Drupal\Tests\language\Functional;
+
+use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
+use Drupal\Core\Url;
+use Drupal\language\Plugin\LanguageNegotiation\LanguageNegotiationUrl;
+use Drupal\Tests\BrowserTestBase;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * Tests that URL rewriting works as expected.
+ *
+ * @group language
+ */
+class LanguageUrlRewritingTest extends BrowserTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['language', 'language_test'];
+
+ /**
+ * An user with permissions to administer languages.
+ *
+ * @var \Drupal\user\UserInterface
+ */
+ protected $webUser;
+
+ protected function setUp() {
+ parent::setUp();
+
+ // Create and log in user.
+ $this->webUser = $this->drupalCreateUser(['administer languages', 'access administration pages']);
+ $this->drupalLogin($this->webUser);
+
+ // Install French language.
+ $edit = [];
+ $edit['predefined_langcode'] = 'fr';
+ $this->drupalPostForm('admin/config/regional/language/add', $edit, t('Add language'));
+
+ // Enable URL language detection and selection.
+ $edit = ['language_interface[enabled][language-url]' => 1];
+ $this->drupalPostForm('admin/config/regional/language/detection', $edit, t('Save settings'));
+
+ // Check that drupalSettings contains path prefix.
+ $this->drupalGet('fr/admin/config/regional/language/detection');
+ $this->assertRaw('"pathPrefix":"fr\/"', 'drupalSettings path prefix contains language code.');
+ }
+
+ /**
+ * Check that non-installed languages are not considered.
+ */
+ public function testUrlRewritingEdgeCases() {
+ // Check URL rewriting with a non-installed language.
+ $non_existing = new Language(['id' => $this->randomMachineName()]);
+ $this->checkUrl($non_existing, 'Path language is ignored if language is not installed.', 'URL language negotiation does not work with non-installed languages');
+
+ // Check that URL rewriting is not applied to subrequests.
+ $this->drupalGet('language_test/subrequest');
+ $this->assertText($this->webUser->getUsername(), 'Page correctly retrieved');
+ }
+
+ /**
+ * Check URL rewriting for the given language.
+ *
+ * The test is performed with a fixed URL (the default front page) to simply
+ * check that language prefixes are not added to it and that the prefixed URL
+ * is actually not working.
+ *
+ * @param \Drupal\Core\Language\LanguageInterface $language
+ * The language object.
+ * @param string $message1
+ * Message to display in assertion that language prefixes are not added.
+ * @param string $message2
+ * The message to display confirming prefixed URL is not working.
+ */
+ private function checkUrl(LanguageInterface $language, $message1, $message2) {
+ $options = ['language' => $language, 'script' => ''];
+ $base_path = trim(base_path(), '/');
+ $rewritten_path = trim(str_replace($base_path, '', \Drupal::url('<front>', [], $options)), '/');
+ $segments = explode('/', $rewritten_path, 2);
+ $prefix = $segments[0];
+ $path = isset($segments[1]) ? $segments[1] : $prefix;
+
+ // If the rewritten URL has not a language prefix we pick a random prefix so
+ // we can always check the prefixed URL.
+ $prefixes = language_negotiation_url_prefixes();
+ $stored_prefix = isset($prefixes[$language->getId()]) ? $prefixes[$language->getId()] : $this->randomMachineName();
+ $this->assertNotEqual($stored_prefix, $prefix, $message1);
+ $prefix = $stored_prefix;
+
+ $this->drupalGet("$prefix/$path");
+ $this->assertResponse(404, $message2);
+ }
+
+ /**
+ * Check URL rewriting when using a domain name and a non-standard port.
+ */
+ public function testDomainNameNegotiationPort() {
+ global $base_url;
+ $language_domain = 'example.fr';
+ // Get the current host URI we're running on.
+ $base_url_host = parse_url($base_url, PHP_URL_HOST);
+ $edit = [
+ 'language_negotiation_url_part' => LanguageNegotiationUrl::CONFIG_DOMAIN,
+ 'domain[en]' => $base_url_host,
+ 'domain[fr]' => $language_domain
+ ];
+ $this->drupalPostForm('admin/config/regional/language/detection/url', $edit, t('Save configuration'));
+ // Rebuild the container so that the new language gets picked up by services
+ // that hold the list of languages.
+ $this->rebuildContainer();
+
+ // Enable domain configuration.
+ $this->config('language.negotiation')
+ ->set('url.source', LanguageNegotiationUrl::CONFIG_DOMAIN)
+ ->save();
+
+ // Reset static caching.
+ $this->container->get('language_manager')->reset();
+
+ // In case index.php is part of the URLs, we need to adapt the asserted
+ // URLs as well.
+ $index_php = strpos(\Drupal::url('<front>', [], ['absolute' => TRUE]), 'index.php') !== FALSE;
+
+ $request = Request::createFromGlobals();
+ $server = $request->server->all();
+ $request = $this->prepareRequestForGenerator(TRUE, ['HTTP_HOST' => $server['HTTP_HOST'] . ':88']);
+
+ // Create an absolute French link.
+ $language = \Drupal::languageManager()->getLanguage('fr');
+ $url = Url::fromRoute('<front>', [], [
+ 'absolute' => TRUE,
+ 'language' => $language,
+ ])->toString();
+
+ $expected = ($index_php ? 'http://example.fr:88/index.php' : 'http://example.fr:88') . rtrim(base_path(), '/') . '/';
+
+ $this->assertEqual($url, $expected, 'The right port is used.');
+
+ // If we set the port explicitly, it should not be overridden.
+ $url = Url::fromRoute('<front>', [], [
+ 'absolute' => TRUE,
+ 'language' => $language,
+ 'base_url' => $request->getBaseUrl() . ':90',
+ ])->toString();
+
+ $expected = $index_php ? 'http://example.fr:90/index.php' : 'http://example.fr:90' . rtrim(base_path(), '/') . '/';
+
+ $this->assertEqual($url, $expected, 'A given port is not overridden.');
+
+ }
+
+}