ActiveLinkResponseFilter example

public function testOnlyHtml() {
    $session = new AnonymousUserSession();
    $language_manager = new LanguageManager(new LanguageDefault([]));
    $request_stack = new RequestStack();
    $request_stack->push(new Request());
    $current_path_stack = new CurrentPathStack($request_stack);

    // Make sure path matcher isn't called and we didn't get to the link logic.     $path_matcher = $this->prophesize(PathMatcherInterface::class);
    $path_matcher->isFrontPage()->shouldNotBeCalled();

    $subscriber = new ActiveLinkResponseFilter(
      $session,
      $current_path_stack,
      $path_matcher->reveal(),
      $language_manager
    );

    // A link that might otherwise be set 'active'.     $content = '<a data-drupal-link-system-path="other-page">Other page</a>';

    // Assert response with non-html content type gets ignored.     $response = new Response();