Issue #3300773 by bradjones1, xjm, catch, andypost, Spokje: Fix failed test on...

 */

class TestControllers {

  const LONG_TEXT = 'This is text long enough to trigger Apache mod_deflate to add a `vary: accept-encoding` header to the response.';

  public function test() {

    return new Response('test');

  }

  public function test1() {

    return new Response('test1');

    return new Response(self::LONG_TEXT);

  }

  public function test2() {

use Drupal\Core\Cache\Cache;

use Drupal\Core\EventSubscriber\MainContentViewSubscriber;

use Drupal\Core\Language\LanguageInterface;

use Drupal\router_test\TestControllers;

use Drupal\Tests\BrowserTestBase;

use Symfony\Component\Routing\Exception\RouteNotFoundException;

use Drupal\Core\Url;

    // Confirm that the router can get to a controller.

    $this->drupalGet('router_test/test1');

    $this->assertSession()->pageTextContains('test1');

    $this->assertSession()->pageTextContains(TestControllers::LONG_TEXT);

    $session = $this->getSession();

    // Check expected headers from FinishResponseSubscriber.

    $this->assertSession()->responseHeaderEquals('Content-language', 'en');

    $this->assertSession()->responseHeaderEquals('X-Content-Type-Options', 'nosniff');

    $this->assertSession()->responseHeaderEquals('X-Frame-Options', 'SAMEORIGIN');

    if (strcasecmp($session->getResponseHeader('vary'), 'accept-encoding') !== 0) {

      $this->assertSession()->responseHeaderDoesNotExist('Vary');

    }

    $this->drupalGet('router_test/test2');

    $this->assertSession()->pageTextContains('test2');