[5.5] Fix NotificationFake interfaces and return fake object.

src/Illuminate/Support/Facades/Notification.php

@@ -14,11 +14,13 @@ class Notification extends Facade
     /**
      * Replace the bound instance with a fake.
      *
-     * @return void
+     * @return \Illuminate\Support\Testing\Fakes\NotificationFake
      */
     public static function fake()
     {
-        static::swap(new NotificationFake);
+        static::swap($fake = new NotificationFake);
+
+        return $fake;
     }
 
     /**

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

@@ -6,8 +6,9 @@
 use Illuminate\Support\Collection;
 use PHPUnit\Framework\Assert as PHPUnit;
 use Illuminate\Contracts\Notifications\Factory as NotificationFactory;
+use Illuminate\Contracts\Notifications\Dispatcher as NotificationDispatcher;
 
-class NotificationFake implements NotificationFactory
+class NotificationFake implements NotificationFactory, NotificationDispatcher
 {
     /**
      * All of the notifications that have been sent.

tests/Integration/Notifications/SendingNotificationsViaAnonymousNotifiableTest.php

@@ -5,6 +5,7 @@
 use Orchestra\Testbench\TestCase;
 use Illuminate\Notifications\Notification;
 use Illuminate\Notifications\AnonymousNotifiable;
+use Illuminate\Support\Testing\Fakes\NotificationFake;
 use Illuminate\Support\Facades\Notification as NotificationFacade;
 
 /**
@@ -37,7 +38,9 @@ public function test_mail_is_sent()
 
     public function test_faking()
     {
-        NotificationFacade::fake();
+        $fake = NotificationFacade::fake();
+
+        $this->assertInstanceOf(NotificationFake::class, $fake);
 
         $notifiable = (new AnonymousNotifiable())
             ->route('testchannel', 'enzo')