return null explicitly when player_id is empty, added tests for channel return values

Author: pavoltanuska

src/OneSignalChannel.php

@@ -29,7 +29,7 @@ public function __construct(OneSignalClient $oneSignal)
     public function send($notifiable, Notification $notification)
     {
         if (! $userIds = $notifiable->routeNotificationFor('OneSignal')) {
-            return;
+            return null;
         }
 
         $payload = $notification->toOneSignal($notifiable)->toArray();

tests/ChannelTest.php

@@ -8,6 +8,7 @@
 use Berkayk\OneSignal\OneSignalClient;
 use NotificationChannels\OneSignal\OneSignalChannel;
 use NotificationChannels\OneSignal\Exceptions\CouldNotSendNotification;
+use Psr\Http\Message\ResponseInterface;
 
 class ChannelTest extends TestCase
 {
@@ -52,7 +53,9 @@ public function it_can_send_a_notification()
             ])
             ->andReturn($response);
 
-        $this->channel->send(new Notifiable(), new TestNotification());
+        $channel_response = $this->channel->send(new Notifiable(), new TestNotification());
+
+        $this->assertInstanceOf(ResponseInterface::class, $channel_response);
     }
 
     /** @test */
@@ -104,6 +107,18 @@ public function it_can_send_a_notification_with_email()
             ])
             ->andReturn($response);
 
-        $this->channel->send(new NotifiableEmail(), new TestNotification());
+        $channel_response = $this->channel->send(new NotifiableEmail(), new TestNotification());
+
+        $this->assertInstanceOf(ResponseInterface::class, $channel_response);
+    }
+
+    /** @test */
+    public function it_sends_nothing_and_returns_null_when_player_id_empty()
+    {
+        $this->oneSignal->shouldReceive('sendNotificationCustom')
+            ->never();
+
+        $channel_response = $this->channel->send(new EmptyNotifiable(), new TestNotification());
+        $this->assertNull($channel_response);
     }
 }

tests/EmptyNotifiable.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace NotificationChannels\OneSignal\Test;
+
+class EmptyNotifiable
+{
+    use \Illuminate\Notifications\Notifiable;
+
+    /**
+     * @return int
+     */
+    public function routeNotificationForOneSignal()
+    {
+        return '';
+    }
+}