--- /dev/null
+<?php
+
+namespace Drupal\Tests\system\Kernel\Theme;
+
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests Drupal's Twig filters.
+ *
+ * @group Theme
+ */
+class TwigFilterTest extends KernelTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['twig_theme_test'];
+
+ /**
+ * Test Twig "without" filter.
+ */
+ public function testTwigWithoutFilter() {
+ $filter_test = [
+ '#theme' => 'twig_theme_test_filter',
+ '#quote' => [
+ 'content' => ['#markup' => 'You can only find truth with logic if you have already found truth without it.'],
+ 'author' => ['#markup' => 'Gilbert Keith Chesterton'],
+ 'date' => ['#markup' => '1874-1936'],
+ ],
+ '#attributes' => [
+ 'id' => 'quotes',
+ 'checked' => TRUE,
+ 'class' => ['red', 'green', 'blue'],
+ ],
+ ];
+ $rendered = \Drupal::service('renderer')->renderRoot($filter_test);
+ $this->setRawContent($rendered);
+
+ $elements = [
+ [
+ 'expected' => '<div><strong>No author:</strong> You can only find truth with logic if you have already found truth without it.1874-1936.</div>',
+ 'message' => '"No author" was successfully rendered.',
+ ],
+ [
+ 'expected' => '<div><strong>Complete quote after without:</strong> You can only find truth with logic if you have already found truth without it.Gilbert Keith Chesterton1874-1936.</div>',
+ 'message' => '"Complete quote after without" was successfully rendered.',
+ ],
+ [
+ 'expected' => '<div><strong>Only author:</strong> Gilbert Keith Chesterton.</div>',
+ 'message' => '"Only author:" was successfully rendered.',
+ ],
+ [
+ 'expected' => '<div><strong>No author or date:</strong> You can only find truth with logic if you have already found truth without it..</div>',
+ 'message' => '"No author or date" was successfully rendered.',
+ ],
+ [
+ 'expected' => '<div><strong>Only date:</strong> 1874-1936.</div>',
+ 'message' => '"Only date" was successfully rendered.',
+ ],
+ [
+ 'expected' => '<div><strong>Complete quote again for good measure:</strong> You can only find truth with logic if you have already found truth without it.Gilbert Keith Chesterton1874-1936.</div>',
+ 'message' => '"Complete quote again for good measure" was successfully rendered.',
+ ],
+ [
+ 'expected' => '<div><strong>Marked-up:</strong>
+ <blockquote>
+ <p>You can only find truth with logic if you have already found truth without it.</p>
+ <footer>
+ – <cite><a href="#">Gilbert Keith Chesterton</a> <em>(1874-1936)</em></cite>
+ </footer>
+ </blockquote>',
+ 'message' => '"Marked-up quote" was successfully rendered.',
+ ],
+ [
+ 'expected' => '<div><span id="quotes" checked class="red green blue">All attributes:</span></div>',
+ 'message' => 'All attributes printed.',
+ ],
+ [
+ 'expected' => '<div><span class="red green blue" id="quotes" checked>Class attributes in front, remainder at the back:</span></div>',
+ 'message' => 'Class attributes printed in the front, the rest in the back.',
+ ],
+ [
+ 'expected' => '<div><span id="quotes" checked data-class="red green blue">Class attributes in back, remainder at the front:</span></div>',
+ 'message' => 'Class attributes printed in the back, the rest in the front.',
+ ],
+ [
+ 'expected' => '<div><span class="red green blue">Class attributes only:</span></div>',
+ 'message' => 'Class attributes only printed.',
+ ],
+ [
+ 'expected' => '<div><span checked id="quotes" class="red green blue">Without boolean attribute.</span></div>',
+ 'message' => 'Boolean attribute printed in the front.',
+ ],
+ [
+ 'expected' => '<div><span data-id="quotes" checked class="red green blue">Without string attribute.</span></div>',
+ 'message' => 'Without string attribute in the front.',
+ ],
+ [
+ 'expected' => '<div><span checked>Without id and class attributes.</span></div>',
+ 'message' => 'Attributes printed without id and class attributes.',
+ ],
+ [
+ 'expected' => '<div><span id="quotes" checked class="red green blue">All attributes again.</span></div>',
+ 'message' => 'All attributes printed again.',
+ ],
+ [
+ 'expected' => '<div id="quotes-here"><span class="gray-like-a-bunny bem__ized--top-feature" id="quotes-here">ID and class. Having the same ID twice is not valid markup but we want to make sure the filter doesn\'t use \Drupal\Component\Utility\Html::getUniqueId().</span></div>',
+ 'message' => 'Class and ID filtered.',
+ ],
+ [
+ 'expected' => '<div><strong>Rendered author string length:</strong> 24.</div>',
+ 'message' => 'Render filter string\'s length.',
+ ],
+ ];
+
+ foreach ($elements as $element) {
+ $this->assertRaw($element['expected'], $element['message']);
+ }
+ }
+
+}