Add method to clear notification when user is deletd

Added a method to clear notification entry of user
when the user is deleted from oC.

Signed-off-by: Sujith H <sharidasan@owncloud.com>

lib/private/Notification/Manager.php

@@ -22,6 +22,7 @@
 
 namespace OC\Notification;
 
+use OCP\IUser;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use OCP\Notification\IApp;
 use OCP\Notification\IManager;
@@ -32,6 +33,7 @@
 use OCP\Notification\Events\RegisterNotifierEvent;
 use OC\Notification\Events\RegisterConsumerEventImpl;
 use OC\Notification\Events\RegisterNotifierEventImpl;
+use Symfony\Component\EventDispatcher\GenericEvent;
 
 class Manager implements IManager {
 	/** @var EventDispatcherInterface */
@@ -72,6 +74,10 @@ public function __construct(EventDispatcherInterface $dispatcher) {
 		$this->notifiersInfoClosures = [];
 
 		$this->builtAppsHolder = [];
+
+		$this->dispatcher->addListener('user.afterdelete', function (GenericEvent $event) {
+			$this->removeUserNotifications($event->getArgument('uid'));
+		});
 	}
 
 	/**
@@ -299,4 +305,12 @@ public function getCount(INotification $notification) {
 
 		return $count;
 	}
+
+	public function removeUserNotifications($uid) {
+		$apps = $this->getApps();
+
+		foreach ($apps as $app) {
+			$app->removeUserNotifications($uid);
+		}
+	}
 }

lib/public/Notification/IApp.php

@@ -49,4 +49,11 @@ public function markProcessed(INotification $notification);
 	 * @since 9.0.0
 	 */
 	public function getCount(INotification $notification);
+
+	/**
+	 * @param $uid
+	 * @return null
+	 * @since 10.1.0
+	 */
+	public function removeUserNotifications($uid);
 }

tests/lib/Notification/ManagerTest.php

@@ -645,4 +645,17 @@ public function testGetCount() {
 
 		$this->assertSame(63, $this->manager->getCount($notification));
 	}
+
+	public function testRemoveUserNotifications() {
+		$app = $this->createMock(IApp::class);
+		$app->expects($this->once())
+			->method('removeUserNotifications')
+			->with('foo');
+
+		$this->manager->registerApp(function () use ($app) {
+			return $app;
+		});
+
+		$this->manager->removeUserNotifications('foo');
+	}
 }