Issue #3326524: Content of drupalSettings.bestreply not up-to-date

bestreply.module

@@ -52,6 +52,12 @@ function bestreply_node_view(array &$build, EntityInterface $entity, EntityViewD
     $build['#attached']['drupalSettings']['bestreply']['name'] = $br_name;
     $build['#attached']['drupalSettings']['bestreply']['ismarked'] = $br_id;
 
+    // Add cache tags that can be invalidated if best reply is marked or cleared such that
+    // drupalSettings are always up-to-date.
+    $build['#cache'] = [
+      'tags' => ['bestreply:node:' . $entity->id()]
+    ];
+
     if ($if_comments_available && $br_id && \Drupal::currentUser()->hasPermission('view bestreply')) {
       $bestreply_comment_link = t('View @bestreply.', ['@bestreply' => $br_name]);
       $links['bestreply-view'] = [

src/Controller/BestReplyController.php

@@ -3,6 +3,7 @@
 namespace Drupal\bestreply\Controller;
 
 use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\Config\ConfigFactory;
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\comment\CommentInterface;
@@ -141,6 +142,9 @@ class BestReplyController extends ControllerBase implements ContainerInjectionIn
               'dt' => $dt,
             ]);
       }
+
+      Cache::invalidateTags(['bestreply:node:' . $comment->getCommentedEntityId()]);
+
       if ($js) {
         $status = ($rt) ? TRUE : FALSE;
         print Json::encode([
@@ -159,6 +163,7 @@ class BestReplyController extends ControllerBase implements ContainerInjectionIn
   public function clear(CommentInterface $comment, $js = NULL) {
     if (bestreply_ismarked($comment->getCommentedEntityId())) {
       $rt = $this->connection->query("DELETE FROM {bestreply} WHERE nid = :nid", ['nid' => $comment->getCommentedEntityId()]);
+      Cache::invalidateTags(['bestreply:node:' . $comment->getCommentedEntityId()]);
     }
     if ($js) {
       $status = ($rt) ? TRUE : FALSE;