[7.x] Fix serialization of models when sending notifications

src/Illuminate/Notifications/SendQueuedNotifications.php

@@ -4,6 +4,8 @@
 
 use Illuminate\Bus\Queueable;
 use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Database\Eloquent\Collection as EloquentCollection;
+use Illuminate\Database\Eloquent\Model;
 use Illuminate\Queue\InteractsWithQueue;
 use Illuminate\Queue\SerializesModels;
 use Illuminate\Support\Collection;
@@ -50,7 +52,7 @@ class SendQueuedNotifications implements ShouldQueue
     /**
      * Create a new job instance.
      *
-     * @param  \Illuminate\Support\Collection  $notifiables
+     * @param  \Illuminate\Notifications\Notifiable|\Illuminate\Support\Collection  $notifiables
      * @param  \Illuminate\Notifications\Notification  $notification
      * @param  array|null  $channels
      * @return void
@@ -59,7 +61,7 @@ public function __construct($notifiables, $notification, array $channels = null)
     {
         $this->channels = $channels;
         $this->notification = $notification;
-        $this->notifiables = Collection::wrap($notifiables);
+        $this->notifiables = $this->wrapNotifiables($notifiables);
         $this->tries = property_exists($notification, 'tries') ? $notification->tries : null;
         $this->timeout = property_exists($notification, 'timeout') ? $notification->timeout : null;
     }
@@ -136,4 +138,27 @@ public function __clone()
         $this->notifiables = clone $this->notifiables;
         $this->notification = clone $this->notification;
     }
+
+    /**
+     * Wrap the notifiable(s) in a collection.
+     *
+     * @param  \Illuminate\Notifications\Notifiable|\Illuminate\Support\Collection  $notifiables
+     * @return \Illuminate\Support\Collection
+     */
+    protected function wrapNotifiables($notifiables)
+    {
+        if ($notifiables instanceof Collection) {
+            // If the notifiable(s) are already wrapped, pass them as is.
+            // This prevents any custom queueable collections from being re-wrapped
+            return $notifiables;
+        }
+
+        if ($notifiables instanceof Model) {
+            // In the case of a model we want to wrap it in an eloquent collection
+            // This way the job can take advantage of model serialization
+            return EloquentCollection::wrap($notifiables);
+        }
+
+        return Collection::wrap($notifiables);
+    }
 }

tests/Notifications/NotificationSendQueuedNotificationTest.php

@@ -2,9 +2,12 @@
 
 namespace Illuminate\Tests\Notifications;
 
+use Illuminate\Contracts\Database\ModelIdentifier;
+use Illuminate\Notifications\AnonymousNotifiable;
 use Illuminate\Notifications\ChannelManager;
 use Illuminate\Notifications\SendQueuedNotifications;
 use Illuminate\Support\Collection;
+use Illuminate\Tests\Integration\Notifications\NotifiableUser;
 use Mockery as m;
 use PHPUnit\Framework\TestCase;
 
@@ -26,4 +29,26 @@ public function testNotificationsCanBeSent()
         });
         $job->handle($manager);
     }
+
+    public function testSerializationOfNotifiableModel()
+    {
+        $identifier = new ModelIdentifier(NotifiableUser::class, [null], [], null);
+        $serializedIdentifier = serialize($identifier);
+
+        $job = new SendQueuedNotifications(new NotifiableUser(), 'notification');
+        $serialized = serialize($job);
+
+        $this->assertStringContainsString($serializedIdentifier, $serialized);
+    }
+
+    public function testSerializationOfNormalNotifiable()
+    {
+        $notifiable = new AnonymousNotifiable();
+        $serializedNotifiable = serialize($notifiable);
+
+        $job = new SendQueuedNotifications($notifiable, 'notification');
+        $serialized = serialize($job);
+
+        $this->assertStringContainsString($serializedNotifiable, $serialized);
+    }
 }