我有一个WelcomeNotification实现了ShouldQueue

class WelcomeNotification extends Notification implements ShouldQueue
{
    use Queueable;

    public function via($notifiable)
    {
        return ['mail'];
    }

    public function toMail($notifiable)
    {
        // send a welcome message to the user via mailtrap
    }

}

如何测试此通知是否已推送到队列？

我正在尝试像这样测试它，但是我正在 The expected [App\Notifications\WelcomeNotification] job was not pushed

    /** @test */
    public function welcome_notification_is_pushed_to_queue()
    {
        Queue::fake();

        $this->post(route('register'),[
            'name' => 'John Doe','email' => 'john@test.com','password' => 'passwordtest',]);

        Queue::assertPushed(WelcomeNotification::class);
    }

在我在RegisterController中注册的功能内：

    protected function registered(Request $request,$user)
    {
          $user->notify(new WelcomeNotification());
          // other code
    }

我已经成功断言了使用WelcomeNotification注册时已正确地将Notification::assertSentTo发送给用户。

我的问题是如何测试WelcomeNotification是否被推入队列？