Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/system/tests/https.php

@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * @file
+ * Fake an HTTPS request, for use during testing.
+ *
+ * @todo Fix this to use a new request rather than modifying server variables,
+ *   see http.php.
+ */
+
+use Drupal\Core\Test\TestKernel;
+use Symfony\Component\HttpFoundation\Request;
+
+chdir('../../../..');
+
+$autoloader = require_once 'autoload.php';
+
+// Change to HTTPS.
+$_SERVER['HTTPS'] = 'on';
+foreach ($_SERVER as &$value) {
+  $value = str_replace('core/modules/system/tests/https.php', 'index.php', $value);
+  $value = str_replace('http://', 'https://', $value);
+}
+
+$kernel = new TestKernel('testing', $autoloader, TRUE);
+
+$request = Request::createFromGlobals();
+$response = $kernel->handle($request);
+$response->send();
+
+$kernel->terminate($request, $response);