Add user id slug driver (#2787)

src/Http/HttpServiceProvider.php

@@ -13,6 +13,7 @@ use Flarum\Discussion\Discussion;
 use Flarum\Discussion\IdWithTransliteratedSlugDriver;
 use Flarum\Foundation\AbstractServiceProvider;
 use Flarum\Settings\SettingsRepositoryInterface;
+use Flarum\User\IdSlugDriver;
 use Flarum\User\User;
 use Flarum\User\UsernameSlugDriver;
 use Illuminate\Support\Arr;
@@ -38,7 +39,8 @@ class HttpServiceProvider extends AbstractServiceProvider
                     'default' => IdWithTransliteratedSlugDriver::class
                 ],
                 User::class => [
-                    'default' => UsernameSlugDriver::class
+                    'default' => UsernameSlugDriver::class,
+                    'id' => IdSlugDriver::class
                 ],
             ];
         });

src/User/IdSlugDriver.php

@@ -0,0 +1,36 @@
+<?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\User;
+
+use Flarum\Database\AbstractModel;
+use Flarum\Http\SlugDriverInterface;
+
+class IdSlugDriver implements SlugDriverInterface
+{
+    /**
+     * @var UserRepository
+     */
+    protected $users;
+
+    public function __construct(UserRepository $users)
+    {
+        $this->users = $users;
+    }
+
+    public function toSlug(AbstractModel $instance): string
+    {
+        return $instance->id;
+    }
+
+    public function fromSlug(string $slug, User $actor): AbstractModel
+    {
+        return $this->users->findOrFail($slug, $actor);
+    }
+}