--- /dev/null
+<?php
+
+namespace Drupal\Tests\locale\Functional;
+
+use Drupal\language\Entity\ConfigurableLanguage;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests LocaleLookup.
+ *
+ * @group locale
+ */
+class LocaleLocaleLookupTest extends BrowserTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['locale', 'locale_test'];
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setUp() {
+ parent::setUp();
+
+ // Change the language default object to different values.
+ ConfigurableLanguage::createFromLangcode('fr')->save();
+ $this->config('system.site')->set('default_langcode', 'fr')->save();
+
+ $this->drupalLogin($this->rootUser);
+ }
+
+ /**
+ * Tests that there are no circular dependencies.
+ */
+ public function testCircularDependency() {
+ // Ensure that we can enable early_translation_test on a non-english site.
+ $this->drupalPostForm('admin/modules', ['modules[early_translation_test][enable]' => TRUE], t('Install'));
+ $this->assertResponse(200);
+ }
+
+ /**
+ * Test language fallback defaults.
+ */
+ public function testLanguageFallbackDefaults() {
+ $this->drupalGet('');
+ // Ensure state of fallback languages persisted by
+ // locale_test_language_fallback_candidates_locale_lookup_alter() is empty.
+ $this->assertEqual(\Drupal::state()->get('locale.test_language_fallback_candidates_locale_lookup_alter_candidates'), []);
+ // Make sure there is enough information provided for alter hooks.
+ $context = \Drupal::state()->get('locale.test_language_fallback_candidates_locale_lookup_alter_context');
+ $this->assertEqual($context['langcode'], 'fr');
+ $this->assertEqual($context['operation'], 'locale_lookup');
+ }
+
+}