--- /dev/null
+<?php
+
+namespace Drupal\render_array_non_html_subscriber_test;
+
+use Drupal\Core\Controller\ControllerBase;
+use Symfony\Component\HttpFoundation\Response;
+
+class RenderArrayNonHtmlSubscriberTestController extends ControllerBase {
+
+ /**
+ * @return string
+ */
+ public function rawString() {
+ return new Response($this->t('Raw controller response.'));
+ }
+
+ /**
+ * @return array
+ */
+ public function renderArray() {
+ return [
+ '#type' => 'html_tag',
+ '#tag' => 'p',
+ '#value' => $this->t('Controller response successfully rendered.'),
+ ];
+ }
+
+}