ActiveLinkResponseFilterTest.php

<?php

declare (strict_types=1);
namespace Drupal\Tests\Core\EventSubscriber;

use Drupal\Component\Serialization\Json;
use Drupal\Core\EventSubscriber\ActiveLinkResponseFilter;
use Drupal\Core\Language\LanguageDefault;
use Drupal\Core\Language\LanguageManager;
use Drupal\Core\Path\CurrentPathStack;
use Drupal\Core\Path\PathMatcherInterface;
use Drupal\Core\Session\AnonymousUserSession;
use Drupal\Core\Template\Attribute;
use Drupal\Tests\UnitTestCase;
use Symfony\Component\HttpFoundation\BinaryFileResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\StreamedResponse;
use Symfony\Component\HttpKernel\Event\ResponseEvent;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\KernelInterface;
// cspell:ignore svenska

/**
 * @coversDefaultClass \Drupal\Core\EventSubscriber\ActiveLinkResponseFilter
 * @group EventSubscriber
 * @group #slow
 */
class ActiveLinkResponseFilterTest extends UnitTestCase {
    
    /**
     * Provides test data for testSetLinkActiveClass().
     *
     * @see \Drupal\Core\EventSubscriber\ActiveLinkResponseFilter::setLinkActiveClass()
     */
    public static function providerTestSetLinkActiveClass() {
        // Define all the variations that *don't* affect whether or not an
        // "is-active" class is set, but that should remain unchanged:
        // - surrounding HTML
        // - tags for which to test the setting of the "is-active" class
        // - content of said tags
        $edge_case_html5 = '<audio src="foo.ogg">
  <track kind="captions" src="foo.en.vtt" srclang="en" label="English">
  <track kind="captions" src="foo.sv.vtt" srclang="sv" label="Svenska">
</audio>';
        $html = [
            // Simple HTML.
0 => [
                'prefix' => '<div><p>',
                'suffix' => '</p></div>',
            ],
            // Tricky HTML5 example that's unsupported by PHP <=5.4's DOMDocument:
            // https://www.drupal.org/comment/7938201#comment-7938201.
1 => [
                'prefix' => '<div><p>',
                'suffix' => '</p>' . $edge_case_html5 . '</div>',
            ],
            // Multi-byte content *before* the HTML that needs the "is-active" class.
            // cSpell:disable-next-line
2 => [
                'prefix' => '<div><p>αβγδεζηθικλμνξοσὠ</p><p>',
                'suffix' => '</p></div>',
            ],
        ];
        $tags = [
            // Of course, it must work on anchors.
'a',
            // Unfortunately, it must also work on list items.
'li',
            // … and therefore, on *any* tag, really.
'foo',
        ];
        $contents = [
            // Regular content.
'test',
            // Mix of UTF-8 and HTML entities, both must be retained.
'☆ 3 × 4 = €12 and 4 &times; 3 = &euro;12 &#9734',
            // Multi-byte content.
            // cSpell:disable-next-line
'ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ',
            // Text that closely approximates an important attribute, but should be
            // ignored.
'data-drupal-link-system-path=&quot;&lt;front&gt;&quot;',
        ];
        // Define all variations that *do* affect whether or not an "is-active"
        // class is set: all possible situations that can be encountered.
        $situations = [];
        // Situations with context: front page, English, no query.
        $context = [
            'path' => 'my-front-page',
            'front' => TRUE,
            'language' => 'en',
            'query' => [],
        ];
        // Nothing to do.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => [],
        ];
        // Matching path, plus all matching variations.
        $attributes = [
            'data-drupal-link-system-path' => 'my-front-page',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'aria-current' => 'page',
            ],
        ];
        // Matching path, plus all non-matching variations.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Special matching path, plus all variations.
        $attributes = [
            'data-drupal-link-system-path' => '<front>',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'aria-current' => 'page',
            ],
        ];
        // Special matching path, plus all non-matching variations.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Situations with context: non-front page, Dutch, no query.
        $context = [
            'path' => 'llama',
            'front' => FALSE,
            'language' => 'nl',
            'query' => [],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => [],
        ];
        // Matching path, plus all matching variations.
        $attributes = [
            'data-drupal-link-system-path' => 'llama',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'aria-current' => 'page',
            ],
        ];
        // Matching path, plus all non-matching variations.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Special non-matching path, plus all variations.
        $attributes = [
            'data-drupal-link-system-path' => '<front>',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes,
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => '{"foo":"bar"}',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Situations with context: non-front page, Dutch, with query.
        $context = [
            'path' => 'llama',
            'front' => FALSE,
            'language' => 'nl',
            'query' => [
                'foo' => 'bar',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => [],
        ];
        // Matching path, plus all matching variations.
        $attributes = [
            'data-drupal-link-system-path' => 'llama',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        // Matching path, plus all non-matching variations.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Special non-matching path, plus all variations.
        $attributes = [
            'data-drupal-link-system-path' => '<front>',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes,
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Situations with context: non-front page, Dutch, with query.
        $context = [
            'path' => 'llama',
            'front' => FALSE,
            'language' => 'nl',
            'query' => [
                'foo' => 'bar',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => [],
        ];
        // Matching path, plus all matching variations.
        $attributes = [
            'data-drupal-link-system-path' => 'llama',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        // Matching path, plus all non-matching variations.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Special non-matching path, plus all variations.
        $attributes = [
            'data-drupal-link-system-path' => '<front>',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes,
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Situations with context: front page, English, query.
        $context = [
            'path' => 'my-front-page',
            'front' => TRUE,
            'language' => 'en',
            'query' => [
                'foo' => 'bar',
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => [],
        ];
        // Matching path, plus all matching variations.
        $attributes = [
            'data-drupal-link-system-path' => 'my-front-page',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        // Matching path, plus all non-matching variations.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Special matching path, plus all variations.
        $attributes = [
            'data-drupal-link-system-path' => '<front>',
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'aria-current' => 'page',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        // Special matching path, plus all non-matching variations.
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'nl',
                'data-drupal-link-query' => Json::encode([
                    'foo' => 'bar',
                ]),
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'data-drupal-link-query' => TRUE,
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => "",
            ],
        ];
        $situations[] = [
            'context' => $context,
            'is active' => FALSE,
            'attributes' => $attributes + [
                'hreflang' => 'en',
                'data-drupal-link-query' => TRUE,
            ],
        ];
        // Query with unsorted keys must match when the attribute is in sorted form.
        $context = [
            'path' => 'my-front-page',
            'front' => TRUE,
            'language' => 'en',
            'query' => [
                'foo' => 'bar',
                'baz' => 'qux',
            ],
        ];
        $attributes = [
            'data-drupal-link-system-path' => 'my-front-page',
            'data-drupal-link-query' => Json::encode([
                'baz' => 'qux',
                'foo' => 'bar',
            ]),
        ];
        $situations[] = [
            'context' => $context,
            'is active' => TRUE,
            'attributes' => $attributes + [
                'aria-current' => 'page',
            ],
        ];
        // Loop over the surrounding HTML variations.
        $data = [];
        for ($h = 0; $h < count($html); $h++) {
            $html_prefix = $html[$h]['prefix'];
            $html_suffix = $html[$h]['suffix'];
            // Loop over the tag variations.
            for ($t = 0; $t < count($tags); $t++) {
                $tag = $tags[$t];
                // Loop over the tag contents variations.
                for ($c = 0; $c < count($contents); $c++) {
                    $tag_content = $contents[$c];
                    $create_markup = function (Attribute $attributes) use ($html_prefix, $html_suffix, $tag, $tag_content) {
                        return $html_prefix . '<' . $tag . $attributes . '>' . $tag_content . '</' . $tag . '>' . $html_suffix;
                    };
                    // Loop over the situations.
                    for ($s = 0; $s < count($situations); $s++) {
                        $situation = $situations[$s];
                        // Build the source markup.
                        $source_markup = $create_markup(new Attribute($situation['attributes']));
                        // Build the target markup. If no "is-active" class should be set,
                        // the resulting HTML should be identical. Otherwise, it should get
                        // an "is-active" class, either by extending an existing "class"
                        // attribute or by adding a "class" attribute.
                        $target_markup = NULL;
                        if (!$situation['is active']) {
                            $target_markup = $source_markup;
                        }
                        else {
                            $active_attributes = $situation['attributes'];
                            if (!isset($active_attributes['class'])) {
                                $active_attributes['class'] = [];
                            }
                            $active_attributes['class'][] = 'is-active';
                            $target_markup = $create_markup(new Attribute($active_attributes));
                        }
                        $data[] = [
                            $source_markup,
                            $situation['context']['path'],
                            $situation['context']['front'],
                            $situation['context']['language'],
                            $situation['context']['query'],
                            $target_markup,
                        ];
                    }
                }
            }
        }
        // Test case to verify that the 'is-active' class is not added multiple
        // times.
        $data[] = [
            0 => '<a data-drupal-link-system-path="&lt;front&gt;">Once</a> <a data-drupal-link-system-path="&lt;front&gt;">Twice</a>',
            1 => '',
            2 => TRUE,
            3 => 'en',
            4 => [],
            5 => '<a data-drupal-link-system-path="&lt;front&gt;" class="is-active" aria-current="page">Once</a> <a data-drupal-link-system-path="&lt;front&gt;" class="is-active" aria-current="page">Twice</a>',
        ];
        // Test cases to verify that the 'is-active' class is added when on the
        // front page, and there are two different kinds of matching links on the
        // page:
        // - the matching path (the resolved front page path)
        // - the special matching path ('<front>')
        $front_special_link = '<a data-drupal-link-system-path="&lt;front&gt;">Front</a>';
        $front_special_link_active = '<a data-drupal-link-system-path="&lt;front&gt;" class="is-active" aria-current="page">Front</a>';
        $front_path_link = '<a data-drupal-link-system-path="my-front-page">Front Path</a>';
        $front_path_link_active = '<a data-drupal-link-system-path="my-front-page" class="is-active" aria-current="page">Front Path</a>';
        $data[] = [
            0 => $front_path_link . ' ' . $front_special_link,
            1 => 'my-front-page',
            2 => TRUE,
            3 => 'en',
            4 => [],
            5 => $front_path_link_active . ' ' . $front_special_link_active,
        ];
        $data[] = [
            0 => $front_special_link . ' ' . $front_path_link,
            1 => 'my-front-page',
            2 => TRUE,
            3 => 'en',
            4 => [],
            5 => $front_special_link_active . ' ' . $front_path_link_active,
        ];
        // Test cases to verify that links to the front page do not get the
        // 'is-active' class when not on the front page.
        $other_link = '<a data-drupal-link-system-path="other-page">Other page</a>';
        $other_link_active = '<a data-drupal-link-system-path="other-page" class="is-active" aria-current="page">Other page</a>';
        $data['<front>-and-other-link-on-other-path'] = [
            0 => $front_special_link . ' ' . $other_link,
            1 => 'other-page',
            2 => FALSE,
            3 => 'en',
            4 => [],
            5 => $front_special_link . ' ' . $other_link_active,
        ];
        $data['front-and-other-link-on-other-path'] = [
            0 => $front_path_link . ' ' . $other_link,
            1 => 'other-page',
            2 => FALSE,
            3 => 'en',
            4 => [],
            5 => $front_path_link . ' ' . $other_link_active,
        ];
        $data['other-and-<front>-link-on-other-path'] = [
            0 => $other_link . ' ' . $front_special_link,
            1 => 'other-page',
            2 => FALSE,
            3 => 'en',
            4 => [],
            5 => $other_link_active . ' ' . $front_special_link,
        ];
        $data['other-and-front-link-on-other-path'] = [
            0 => $other_link . ' ' . $front_path_link,
            1 => 'other-page',
            2 => FALSE,
            3 => 'en',
            4 => [],
            5 => $other_link_active . ' ' . $front_path_link,
        ];
        return $data;
    }
    
    /**
     * Tests setLinkActiveClass().
     *
     * @param string $html_markup
     *   The original HTML markup.
     * @param string $current_path
     *   The system path of the currently active page.
     * @param bool $is_front
     *   Whether the current page is the front page (which implies the current
     *   path might also be <front>).
     * @param string $url_language
     *   The language code of the current URL.
     * @param array $query
     *   The query string for the current URL.
     * @param string $expected_html_markup
     *   The expected updated HTML markup.
     *
     * @dataProvider providerTestSetLinkActiveClass
     * @covers ::setLinkActiveClass
     */
    public function testSetLinkActiveClass($html_markup, $current_path, $is_front, $url_language, array $query, $expected_html_markup) : void {
        $this->assertSame($expected_html_markup, ActiveLinkResponseFilter::setLinkActiveClass($html_markup, $current_path, $is_front, $url_language, $query));
    }
    
    /**
     * Tests ActiveLinkResponseFilter only affects HTML responses.
     *
     * @covers ::onResponse
     */
    public function testOnlyHtml() : void {
        $session = new AnonymousUserSession();
        $language_manager = new LanguageManager(new LanguageDefault([]));
        $request_stack = new RequestStack();
        $request_stack->push(new Request());
        $current_path_stack = new CurrentPathStack($request_stack);
        // Make sure path matcher isn't called and we didn't get to the link logic.
        $path_matcher = $this->prophesize(PathMatcherInterface::class);
        $path_matcher->isFrontPage()
            ->shouldNotBeCalled();
        $subscriber = new ActiveLinkResponseFilter($session, $current_path_stack, $path_matcher->reveal(), $language_manager);
        // A link that might otherwise be set 'active'.
        $content = '<a data-drupal-link-system-path="other-page">Other page</a>';
        // Assert response with non-html content type gets ignored.
        $response = new Response();
        $response->setContent($content);
        $response->headers
            ->get('Content-Type', 'application/json');
        $subscriber->onResponse(new ResponseEvent($this->prophesize(KernelInterface::class)
            ->reveal(), $request_stack->getCurrentRequest(), HttpKernelInterface::MAIN_REQUEST, $response));
        $this->assertSame($response->getContent(), $content);
    }
    
    /**
     * Tests certain response types ignored by the ActiveLinkResponseFilter.
     *
     * @covers ::onResponse
     */
    public function testSkipCertainResponseTypes() : void {
        $session = new AnonymousUserSession();
        $language_manager = new LanguageManager(new LanguageDefault([]));
        $request_stack = new RequestStack();
        $request_stack->push(new Request());
        $current_path_stack = new CurrentPathStack($request_stack);
        // Ensure path matcher is not called. This also tests that the
        // ActiveLinkResponseFilter ignores the response.
        $path_matcher = $this->prophesize(PathMatcherInterface::class);
        $path_matcher->isFrontPage()
            ->shouldNotBeCalled();
        $subscriber = new ActiveLinkResponseFilter($session, $current_path_stack, $path_matcher->reveal(), $language_manager);
        // Test BinaryFileResponse is ignored. Calling setContent() would throw a
        // logic exception.
        $response = new BinaryFileResponse(__FILE__, 200, [
            'Content-Type' => 'text/html',
        ]);
        $subscriber->onResponse(new ResponseEvent($this->prophesize(KernelInterface::class)
            ->reveal(), $request_stack->getCurrentRequest(), HttpKernelInterface::MAIN_REQUEST, $response));
        // Test StreamedResponse is ignored. Calling setContent() would throw a
        // logic exception.
        $response = new StreamedResponse(function () {
            echo 'Success!';
        }, 200, [
            'Content-Type' => 'text/html',
        ]);
        $subscriber->onResponse(new ResponseEvent($this->prophesize(KernelInterface::class)
            ->reveal(), $request_stack->getCurrentRequest(), HttpKernelInterface::MAIN_REQUEST, $response));
    }

}