--- /dev/null
+<?php
+
+namespace Drupal\Tests\views_ui\Kernel;
+
+use Drupal\Tests\views\Kernel\ViewsKernelTestBase;
+use Drupal\views_ui\Controller\ViewsUIController;
+use Drupal\Component\Utility\Html;
+use Drupal\views\Entity\View;
+
+/**
+ * Tests the views ui tagging functionality.
+ *
+ * @group views_ui
+ */
+class TagTest extends ViewsKernelTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['views', 'views_ui', 'user'];
+
+ /**
+ * Tests the views_ui_autocomplete_tag function.
+ */
+ public function testViewsUiAutocompleteTag() {
+ \Drupal::moduleHandler()->loadInclude('views_ui', 'inc', 'admin');
+
+ // Save 15 views with a tag.
+ $tags = [];
+ for ($i = 0; $i < 16; $i++) {
+ $suffix = $i % 2 ? 'odd' : 'even';
+ $tag = 'autocomplete_tag_test_' . $suffix . $this->randomMachineName();
+ $tags[] = $tag;
+ View::create(['tag' => $tag, 'id' => $this->randomMachineName()])->save();
+ }
+
+ // Make sure just ten results are returned.
+ $controller = ViewsUIController::create($this->container);
+ $request = $this->container->get('request_stack')->getCurrentRequest();
+ $request->query->set('q', 'autocomplete_tag_test');
+ $result = $controller->autocompleteTag($request);
+ $matches = (array) json_decode($result->getContent(), TRUE);
+ $this->assertEqual(count($matches), 10, 'Make sure the maximum amount of tag results is 10.');
+
+ // Make sure the returned array has the proper format.
+ $suggestions = array_map(function ($tag) {
+ return ['value' => $tag, 'label' => Html::escape($tag)];
+ }, $tags);
+ foreach ($matches as $match) {
+ $this->assertTrue(in_array($match, $suggestions), 'Make sure the returned array has the proper format.');
+ }
+
+
+ // Make sure that matching by a certain prefix works.
+ $request->query->set('q', 'autocomplete_tag_test_even');
+ $result = $controller->autocompleteTag($request);
+ $matches = (array) json_decode($result->getContent(), TRUE);
+ $this->assertEqual(count($matches), 8, 'Make sure that only a subset is returned.');
+ foreach ($matches as $tag) {
+ $this->assertTrue(array_search($tag['value'], $tags) !== FALSE, format_string('Make sure the returned tag @tag actually exists.', ['@tag' => $tag['value']]));
+ }
+
+ // Make sure an invalid result doesn't return anything.
+ $request->query->set('q', $this->randomMachineName());
+ $result = $controller->autocompleteTag($request);
+ $matches = (array) json_decode($result->getContent());
+ $this->assertEqual(count($matches), 0, "Make sure an invalid tag doesn't return anything.");
+ }
+
+}