Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/behat/mink-browserkit-driver/tests/Custom/BaseUrlTest.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Behat\Mink\Tests\Driver\Custom;
+
+use Behat\Mink\Driver\BrowserKitDriver;
+use Behat\Mink\Session;
+use Symfony\Component\HttpKernel\Client;
+
+/**
+ * @group functional
+ */
+class BaseUrlTest extends \PHPUnit_Framework_TestCase
+{
+    public function testBaseUrl()
+    {
+        $client = new Client(require(__DIR__.'/../app.php'));
+        $driver = new BrowserKitDriver($client, 'http://localhost/foo/');
+        $session = new Session($driver);
+
+        $session->visit('http://localhost/foo/index.html');
+        $this->assertEquals(200, $session->getStatusCode());
+        $this->assertEquals('http://localhost/foo/index.html', $session->getCurrentUrl());
+    }
+}