Issue #2430379 by quietone, znerol, larowlan: Add explicit test for session...

Issue #2430379 by quietone, znerol, larowlan: Add explicit test for session based language negotiation

(cherry picked from commit 6eff88bf)

core/modules/language/tests/src/Functional/LanguageNegotiationSessionTest.php

+<?php
+
+namespace Drupal\Tests\language\Functional;
+
+use Drupal\Core\Language\LanguageInterface;
+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;
+
+/**
+ * Tests the session language negotiation method.
+ *
+ * @group language
+ */
+class LanguageNegotiationSessionTest extends BrowserTestBase {
+
+  /**
+   * An administrative user to configure the test environment.
+   *
+   * @var \Drupal\user\Entity\User
+   */
+  protected $adminUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['language'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create a new user with permission to manage the languages.
+    $this->adminUser = $this->drupalCreateUser(['administer languages']);
+    $this->drupalLogin($this->adminUser);
+
+    ConfigurableLanguage::createFromLangcode('fr')->save();
+  }
+
+  /**
+   * Tests language negotiation via query/session parameters.
+   */
+  public function testSessionLanguageNegotiationMethod() {
+    $this->drupalGet('admin/config/regional/language/detection');
+
+    // Enable Session and Selected language for interface language detection.
+    $config = $this->config('language.types');
+    $config->set('configurable', [LanguageInterface::TYPE_INTERFACE]);
+    $config->set('negotiation.language_interface.enabled', [
+      LanguageNegotiationSession::METHOD_ID => -6,
+      LanguageNegotiationSelected::METHOD_ID => 12,
+    ]);
+    $config->set('negotiation.language_interface.method_weights', [
+      'language-user-admin' => -10,
+      LanguageNegotiationUrl::METHOD_ID => -8,
+      LanguageNegotiationSession::METHOD_ID => -6,
+      'language-user' => -4,
+      LanguageNegotiationBrowser::METHOD_ID => -2,
+      LanguageNegotiationSelected::METHOD_ID => 12,
+    ]);
+    $config->save();
+
+    // Set language via query parameter.
+    $this->drupalGet('user/' . $this->adminUser->id(), ['query' => ['language' => 'fr']]);
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->responseHeaderEquals('Content-language', 'fr');
+
+    // Verify that the language is persisted in the session.
+    $this->drupalGet('user/' . $this->adminUser->id());
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->responseHeaderEquals('Content-language', 'fr');
+
+    // Set language via query parameter.
+    $this->drupalGet('user/' . $this->adminUser->id(), ['query' => ['language' => 'en']]);
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->responseHeaderEquals('Content-language', 'en');
+
+    // Verify that the language is persisted in the session.
+    $this->drupalGet('admin/config/regional/language');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->responseHeaderEquals('Content-language', 'en');
+  }
+
+}