fix

framework/core/src/Api/Resource/NotificationResource.php

@@ -23,10 +23,13 @@ use Tobyz\JsonApiServer\Pagination\OffsetPagination;
  */
 class NotificationResource extends AbstractDatabaseResource
 {
+    protected bool $initialized = false;
+
     public function __construct(
         protected Dispatcher $bus,
         protected NotificationRepository $notifications,
     ) {
+        $this->initialized = true;
     }
 
     public function type(): string
@@ -63,21 +66,19 @@ class NotificationResource extends AbstractDatabaseResource
                 ->before(function (Context $context) {
                     $context->getActor()->markNotificationsAsRead()->save();
                 })
-                ->defaultInclude([
+                ->defaultInclude(array_filter([
                     'fromUser',
                     'subject',
-                    'subject.discussion'
+                    $this->initialized && count($this->subjectTypes()) > 1
-                ])
+                        ? 'subject.discussion'
+                        : null,
+                ]))
                 ->paginate(),
         ];
     }
 
     public function fields(): array
     {
-        $subjectTypes = $this->api->typesForModels(
-            (new Notification())->getSubjectModels()
-        );
-
         return [
             Schema\Str::make('contentType')
                 ->property('type'),
@@ -87,7 +88,7 @@ class NotificationResource extends AbstractDatabaseResource
             Schema\Boolean::make('isRead')
                 ->writable()
                 ->get(fn (Notification $notification) => (bool) $notification->read_at)
-                ->set(function (Notification $notification, Context $context) {
+                ->set(function (Notification $notification, bool $value, Context $context) {
                     $this->bus->dispatch(
                         new ReadNotification($notification->id, $context->getActor())
                     );
@@ -99,8 +100,15 @@ class NotificationResource extends AbstractDatabaseResource
                 ->type('users')
                 ->includable(),
             Schema\Relationship\ToOne::make('subject')
-                ->collection($subjectTypes)
+                ->collection($this->subjectTypes())
                 ->includable(),
         ];
     }
+
+    protected function subjectTypes(): array
+    {
+        return $this->api->typesForModels(
+            (new Notification())->getSubjectModels()
+        );
+    }
 }

framework/core/src/Foundation/Config.php

@@ -65,7 +65,7 @@ class Config implements ArrayAccess
 
     public function safeModeExtensions(): ?array
     {
-        return $this->data['safe_mode_extensions'];
+        return $this->data['safe_mode_extensions'] ?? null;
     }
 
     private function requireKeys(mixed ...$keys): void

framework/core/tests/integration/api/notifications/UpdateTest.php

@@ -0,0 +1,67 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Tests\integration\api\notifications;
+
+use Flarum\Discussion\Discussion;
+use Flarum\Notification\Notification;
+use Flarum\Post\Post;
+use Flarum\Testing\integration\RetrievesAuthorizedUsers;
+use Flarum\Testing\integration\TestCase;
+use Flarum\User\User;
+
+class UpdateTest extends TestCase
+{
+    use RetrievesAuthorizedUsers;
+
+    /**
+     * @inheritDoc
+     */
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->prepareDatabase([
+            User::class => [
+                $this->normalUser(),
+            ],
+            Discussion::class => [
+                ['id' => 1, 'title' => 'Foo', 'comment_count' => 1, 'user_id' => 2],
+            ],
+            Post::class => [
+                ['id' => 1, 'discussion_id' => 1, 'user_id' => 2, 'type' => 'comment', 'content' => 'Foo'],
+            ],
+            Notification::class => [
+                ['id' => 1, 'user_id' => 2, 'from_user_id' => 1, 'type' => 'discussionRenamed', 'subject_id' => 1, 'read_at' => null],
+            ]
+        ]);
+    }
+
+    /**
+     * @test
+     */
+    public function can_mark_all_as_read()
+    {
+        $response = $this->send(
+            $this->request('PATCH', '/api/notifications/1', [
+                'authenticatedAs' => 2,
+                'json' => [
+                    'data' => [
+                        'type' => 'notifications',
+                        'attributes' => [
+                            'isRead' => true
+                        ],
+                    ],
+                ],
+            ])
+        );
+
+        $this->assertEquals(200, $response->getStatusCode(), (string) $response->getBody());
+    }
+}

framework/core/tests/integration/extenders/ApiSerializerTest.php

@@ -17,6 +17,7 @@ use Flarum\Api\Resource\UserResource;
 use Flarum\Api\Schema;
 use Flarum\Discussion\Discussion;
 use Flarum\Extend;
+use Flarum\Post\Post;
 use Flarum\Testing\integration\RetrievesAuthorizedUsers;
 use Flarum\Testing\integration\TestCase;
 use Flarum\User\User;

php-packages/testing/src/integration/TestCase.php

@@ -208,6 +208,10 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase
                     'unique' => $instance->uniqueKeys ?? null,
                 ];
             } else {
+                if (class_exists($tableOrModelClass) && is_subclass_of($tableOrModelClass, Model::class)) {
+                    $tableOrModelClass = (new $tableOrModelClass)->getTable();
+                }
+
                 $databaseContent[$tableOrModelClass] = [
                     'rows' => $_rows,
                     'unique' => null,