--- /dev/null
+<?php
+
+namespace Drupal\Tests\comment\Functional;
+
+use Drupal\Component\Serialization\Json;
+use Drupal\Core\Language\LanguageInterface;
+use Drupal\comment\CommentInterface;
+use Drupal\Core\Url;
+use Drupal\comment\Entity\Comment;
+
+/**
+ * Tests the 'new' indicator posted on comments.
+ *
+ * @group comment
+ */
+class CommentNewIndicatorTest extends CommentTestBase {
+
+ /**
+ * Use the main node listing to test rendering on teasers.
+ *
+ * @var array
+ *
+ * @todo Remove this dependency.
+ */
+ public static $modules = ['views'];
+
+ /**
+ * Get node "x new comments" metadata from the server for the current user.
+ *
+ * @param array $node_ids
+ * An array of node IDs.
+ *
+ * @return \Psr\Http\Message\ResponseInterface
+ * The HTTP response.
+ */
+ protected function renderNewCommentsNodeLinks(array $node_ids) {
+ $client = $this->getHttpClient();
+ $url = Url::fromRoute('comment.new_comments_node_links');
+
+ return $client->request('POST', $this->buildUrl($url), [
+ 'cookies' => $this->getSessionCookies(),
+ 'http_errors' => FALSE,
+ 'form_params' => [
+ 'node_ids' => $node_ids,
+ 'field_name' => 'comment',
+ ],
+ ]);
+ }
+
+ /**
+ * Tests new comment marker.
+ */
+ public function testCommentNewCommentsIndicator() {
+ // Test if the right links are displayed when no comment is present for the
+ // node.
+ $this->drupalLogin($this->adminUser);
+ $this->drupalGet('node');
+ $this->assertNoLink(t('@count comments', ['@count' => 0]));
+ $this->assertLink(t('Read more'));
+ // Verify the data-history-node-last-comment-timestamp attribute, which is
+ // used by the drupal.node-new-comments-link library to determine whether
+ // a "x new comments" link might be necessary or not. We do this in
+ // JavaScript to prevent breaking the render cache.
+ $this->assertIdentical(0, count($this->xpath('//*[@data-history-node-last-comment-timestamp]')), 'data-history-node-last-comment-timestamp attribute is not set.');
+
+ // Create a new comment. This helper function may be run with different
+ // comment settings so use $comment->save() to avoid complex setup.
+ /** @var \Drupal\comment\CommentInterface $comment */
+ $comment = Comment::create([
+ 'cid' => NULL,
+ 'entity_id' => $this->node->id(),
+ 'entity_type' => 'node',
+ 'field_name' => 'comment',
+ 'pid' => 0,
+ 'uid' => $this->loggedInUser->id(),
+ 'status' => CommentInterface::PUBLISHED,
+ 'subject' => $this->randomMachineName(),
+ 'hostname' => '127.0.0.1',
+ 'langcode' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
+ 'comment_body' => [LanguageInterface::LANGCODE_NOT_SPECIFIED => [$this->randomMachineName()]],
+ ]);
+ $comment->save();
+ $this->drupalLogout();
+
+ // Log in with 'web user' and check comment links.
+ $this->drupalLogin($this->webUser);
+ $this->drupalGet('node');
+ // Verify the data-history-node-last-comment-timestamp attribute. Given its
+ // value, the drupal.node-new-comments-link library would determine that the
+ // node received a comment after the user last viewed it, and hence it would
+ // perform an HTTP request to render the "new comments" node link.
+ $this->assertIdentical(1, count($this->xpath('//*[@data-history-node-last-comment-timestamp="' . $comment->getChangedTime() . '"]')), 'data-history-node-last-comment-timestamp attribute is set to the correct value.');
+ $this->assertIdentical(1, count($this->xpath('//*[@data-history-node-field-name="comment"]')), 'data-history-node-field-name attribute is set to the correct value.');
+ // The data will be pre-seeded on this particular page in drupalSettings, to
+ // avoid the need for the client to make a separate request to the server.
+ $settings = $this->getDrupalSettings();
+ $this->assertEqual($settings['history'], ['lastReadTimestamps' => [1 => 0]]);
+ $this->assertEqual($settings['comment'], [
+ 'newCommentsLinks' => [
+ 'node' => [
+ 'comment' => [
+ 1 => [
+ 'new_comment_count' => 1,
+ 'first_new_comment_link' => Url::fromRoute('entity.node.canonical', ['node' => 1])->setOptions([
+ 'fragment' => 'new',
+ ])->toString(),
+ ],
+ ],
+ ],
+ ],
+ ]);
+ // Pretend the data was not present in drupalSettings, i.e. test the
+ // separate request to the server.
+ $response = $this->renderNewCommentsNodeLinks([$this->node->id()]);
+ $this->assertSame(200, $response->getStatusCode());
+ $json = Json::decode($response->getBody());
+ $expected = [
+ $this->node->id() => [
+ 'new_comment_count' => 1,
+ 'first_new_comment_link' => $this->node->url('canonical', ['fragment' => 'new']),
+ ],
+ ];
+ $this->assertIdentical($expected, $json);
+
+ // Failing to specify node IDs for the endpoint should return a 404.
+ $response = $this->renderNewCommentsNodeLinks([]);
+ $this->assertSame(404, $response->getStatusCode());
+
+ // Accessing the endpoint as the anonymous user should return a 403.
+ $this->drupalLogout();
+ $response = $this->renderNewCommentsNodeLinks([$this->node->id()]);
+ $this->assertSame(403, $response->getStatusCode());
+ $response = $this->renderNewCommentsNodeLinks([]);
+ $this->assertSame(403, $response->getStatusCode());
+ }
+
+}