[11.x] Fix using AsStringable cast on Notifiable's key

src/Illuminate/Support/Testing/Fakes/NotificationFake.php

@@ -279,7 +279,7 @@ public function hasSent($notifiable, $notification)
      */
     protected function notificationsFor($notifiable, $notification)
     {
-        return $this->notifications[get_class($notifiable)][$notifiable->getKey()][$notification] ?? [];
+        return $this->notifications[get_class($notifiable)][(string) $notifiable->getKey()][$notification] ?? [];
     }
 
     /**
@@ -326,7 +326,7 @@ public function sendNow($notifiables, $notification, ?array $channels = null)
                 continue;
             }
 
-            $this->notifications[get_class($notifiable)][$notifiable->getKey()][get_class($notification)][] = [
+            $this->notifications[get_class($notifiable)][(string) $notifiable->getKey()][get_class($notification)][] = [
                 'notification' => $this->serializeAndRestore && $notification instanceof ShouldQueue
                     ? $this->serializeAndRestoreNotification($notification)
                     : $notification,

tests/Integration/Notifications/DatabaseNotificationTest.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Notifications;
+
+use Illuminate\Database\Eloquent\Casts\AsStringable;
+use Illuminate\Database\Eloquent\Concerns\HasUuids;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Notifications\Notifiable;
+use Illuminate\Support\Facades\Notification;
+use Illuminate\Support\Facades\Schema;
+use Orchestra\Testbench\Attributes\DefineDatabase;
+use Orchestra\Testbench\Attributes\WithMigration;
+use Orchestra\Testbench\TestCase;
+
+#[WithMigration('laravel', 'notifications')]
+class DatabaseNotificationTest extends TestCase
+{
+    use RefreshDatabase;
+
+    #[DefineDatabase('defineDatabaseAndConvertUserIdToUuid')]
+    public function testAssertSentToWhenNotifiableHasStringableKey()
+    {
+        Notification::fake();
+
+        $user = UuidUserFactoryStub::new()->create();
+
+        $user->notify(new NotificationStub);
+
+        Notification::assertSentTo($user, NotificationStub::class, function ($notification, $channels, $notifiable) use ($user) {
+            return $notifiable === $user;
+        });
+    }
+
+    /**
+     * Define database and convert User's ID to UUID.
+     *
+     * @param  \Illuminate\Foundation\Application  $app
+     * @return void
+     */
+    protected function defineDatabaseAndConvertUserIdToUuid($app): void
+    {
+        Schema::table('users', function (Blueprint $table) {
+            $table->uuid('id')->change();
+        });
+    }
+}
+
+class UuidUserFactoryStub extends \Orchestra\Testbench\Factories\UserFactory
+{
+    protected $model = UuidUserStub::class;
+}
+
+class UuidUserStub extends \Illuminate\Foundation\Auth\User
+{
+    use HasUuids, Notifiable;
+
+    protected $table = 'users';
+
+    #[\Override]
+    public function casts()
+    {
+        return array_merge(parent::casts(), ['id' => AsStringable::class]);
+    }
+}
+
+class NotificationStub extends \Illuminate\Notifications\Notification
+{
+    public function via($notifiable)
+    {
+        return ['mail'];
+    }
+}