--- /dev/null
+<?php
+
+/**
+ * @file
+ * Helper module for Views UI tests.
+ */
+
+/**
+ * Implements hook_views_preview_info_alter().
+ *
+ * Add a row count row to the live preview area.
+ */
+function views_ui_test_views_preview_info_alter(&$rows, $view) {
+ $data = ['#markup' => t('Test row count')];
+ $data['#attached']['library'][] = 'views_ui_test/views_ui_test.test';
+ $rows['query'][] = [['data' => $data], count($view->result)];
+}