class LanguagePathMonolingualTest

class LanguagePathMonolingualTest extends BrowserTestBase {
  
  /**
   * Modules to enable.
   *
   * @var array
   */
  protected static $modules = [
    'block',
    'language',
    'path',
  ];
  
  /**
   * {@inheritdoc}
   */
  protected $defaultTheme = 'stark';
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    // Create and log in user.
    $web_user = $this->drupalCreateUser([
      'administer languages',
      'access administration pages',
      'administer site configuration',
    ]);
    $this->drupalLogin($web_user);
    // Enable French language.
    $edit = [];
    $edit['predefined_langcode'] = 'fr';
    $this->drupalGet('admin/config/regional/language/add');
    $this->submitForm($edit, 'Add language');
    // Make French the default language.
    $edit = [
      'site_default_language' => 'fr',
    ];
    $this->drupalGet('admin/config/regional/language');
    $this->submitForm($edit, 'Save configuration');
    // Delete English.
    $this->drupalGet('admin/config/regional/language/delete/en');
    $this->submitForm([], 'Delete');
    // Changing the default language causes a container rebuild. Therefore need
    // to rebuild the container in the test environment.
    $this->rebuildContainer();
    // Verify that French is the only language.
    $this->container
      ->get('language_manager')
      ->reset();
    $this->assertFalse(\Drupal::languageManager()->isMultilingual(), 'Site is mono-lingual');
    $this->assertEquals('fr', \Drupal::languageManager()->getDefaultLanguage()
      ->getId(), 'French is the default language');
    // Set language detection to URL.
    $edit = [
      'language_interface[enabled][language-url]' => TRUE,
    ];
    $this->drupalGet('admin/config/regional/language/detection');
    $this->submitForm($edit, 'Save settings');
    $this->drupalPlaceBlock('local_actions_block');
  }
  
  /**
   * Verifies that links do not have language prefixes in them.
   */
  public function testPageLinks() {
    // Navigate to 'admin/config' path.
    $this->drupalGet('admin/config');
    // Verify that links in this page do not have a 'fr/' prefix.
    $this->assertSession()
      ->linkByHrefNotExists('/fr/', 'Links do not contain language prefix');
    // Verify that links in this page can be followed and work.
    $this->clickLink('Languages');
    $this->assertSession()
      ->statusCodeEquals(200);
    $this->assertSession()
      ->pageTextContains('Add language');
  }

}