diff --git a/apps/updatenotification/appinfo/app.php b/apps/updatenotification/appinfo/app.php
index de78da5da7..e9780757cc 100644
--- a/apps/updatenotification/appinfo/app.php
+++ b/apps/updatenotification/appinfo/app.php
@@ -45,7 +45,8 @@ if(\OC::$server->getConfig()->getSystemValue('updatechecker', true) === true) {
 			$manager,
 			\OC::$server->getL10NFactory()
 		);
-	}, function() use ($l) {
+	}, function() {
+		$l = \OC::$server->getL10N('updatenotification');
 		return [
 			'id' => 'updatenotification',
 			'name' => $l->t('Update notifications'),
diff --git a/apps/updatenotification/lib/Controller/AdminController.php b/apps/updatenotification/lib/Controller/AdminController.php
index c622b9690a..2fc12140b2 100644
--- a/apps/updatenotification/lib/Controller/AdminController.php
+++ b/apps/updatenotification/lib/Controller/AdminController.php
@@ -101,7 +101,7 @@ class AdminController extends Controller {
 		}
 		$updateState = $this->updateChecker->getUpdateState();
 
-		$notifyGroups = json_decode($this->config->getAppValue('updatenotification', 'notify_groups', '["admin"]'));
+		$notifyGroups = json_decode($this->config->getAppValue('updatenotification', 'notify_groups', '["admin"]'), true);
 
 		$params = [
 			'isNewVersionAvailable' => ($updateState === []) ? false : true,
diff --git a/apps/updatenotification/lib/Notification/BackgroundJob.php b/apps/updatenotification/lib/Notification/BackgroundJob.php
index f2cf7e1cd8..3a89f3813e 100644
--- a/apps/updatenotification/lib/Notification/BackgroundJob.php
+++ b/apps/updatenotification/lib/Notification/BackgroundJob.php
@@ -82,15 +82,12 @@ class BackgroundJob extends TimedJob {
 	 * Check for ownCloud update
 	 */
 	protected function checkCoreUpdate() {
-		if (in_array(\OC_Util::getChannel(), ['daily', 'git'])) {
+		if (in_array($this->getChannel(), ['daily', 'git'])) {
 			// "These aren't the update channels you're looking for." - Ben Obi-Wan Kenobi
 			return;
 		}
 
-		$updater = new VersionCheck(
-			$this->client,
-			$this->config
-		);
+		$updater = $this->createVersionCheck();
 
 		$status = $updater->check();
 		if (isset($status['version'])) {
@@ -104,7 +101,7 @@ class BackgroundJob extends TimedJob {
 	protected function checkAppUpdates() {
 		$apps = $this->appManager->getInstalledApps();
 		foreach ($apps as $app) {
-			$update = Installer::isUpdateAvailable($app);
+			$update = $this->isUpdateAvailable($app);
 			if ($update !== false) {
 				$this->createNotifications($app, $update);
 			}
@@ -134,8 +131,8 @@ class BackgroundJob extends TimedJob {
 			->setObject($app, $version)
 			->setSubject('update_available');
 
-		foreach ($this->getUsersToNotify() as $user) {
-			$notification->setUser($user->getUID());
+		foreach ($this->getUsersToNotify() as $uid) {
+			$notification->setUser($uid);
 			$this->notificationManager->notify($notification);
 		}
 
@@ -143,21 +140,26 @@ class BackgroundJob extends TimedJob {
 	}
 
 	/**
-	 * @return \OCP\IUser[]
+	 * @return string[]
 	 */
 	protected function getUsersToNotify() {
 		if ($this->users !== null) {
 			return $this->users;
 		}
 
-		$notifyGroups = json_decode($this->config->getAppValue('updatenotification', 'notify_groups', '["admin"]'));
+		$notifyGroups = json_decode($this->config->getAppValue('updatenotification', 'notify_groups', '["admin"]'), true);
+		$this->users = [];
 		foreach ($notifyGroups as $group) {
 			$groupToNotify = $this->groupManager->get($group);
 			if ($groupToNotify instanceof IGroup) {
-				$this->users = array_merge($this->users, $groupToNotify->getUsers());
+				foreach ($groupToNotify->getUsers() as $user) {
+					$this->users[$user->getUID()] = true;
+				}
 			}
 		}
 
+		$this->users = array_keys($this->users);
+
 		return $this->users;
 	}
 
@@ -173,4 +175,29 @@ class BackgroundJob extends TimedJob {
 			->setObject($app, $version);
 		$this->notificationManager->markProcessed($notification);
 	}
+
+	/**
+	 * @return VersionCheck
+	 */
+	protected function createVersionCheck() {
+		return new VersionCheck(
+			$this->client,
+			$this->config
+		);
+	}
+
+	/**
+	 * @return string
+	 */
+	protected function getChannel() {
+		return \OC_Util::getChannel();
+	}
+
+	/**
+	 * @param string $app
+	 * @return string|false
+	 */
+	protected function isUpdateAvailable($app) {
+		return Installer::isUpdateAvailable($app);
+	}
 }
diff --git a/apps/updatenotification/tests/Notification/BackgroundJobTest.php b/apps/updatenotification/tests/Notification/BackgroundJobTest.php
new file mode 100644
index 0000000000..9b920ec4ce
--- /dev/null
+++ b/apps/updatenotification/tests/Notification/BackgroundJobTest.php
@@ -0,0 +1,409 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCA\UpdateNotification\Tests\Notification;
+
+
+use OC\Installer;
+use OC\Updater\VersionCheck;
+use OCA\UpdateNotification\Notification\BackgroundJob;
+use OCP\App\IAppManager;
+use OCP\Http\Client\IClientService;
+use OCP\IConfig;
+use OCP\IGroup;
+use OCP\IGroupManager;
+use OCP\IUser;
+use OCP\Notification\IManager;
+use Test\TestCase;
+
+class BackgroundJobTest extends TestCase {
+
+	/** @var IConfig|\PHPUnit_Framework_MockObject_MockObject */
+	protected $config;
+	/** @var IManager|\PHPUnit_Framework_MockObject_MockObject */
+	protected $notificationManager;
+	/** @var IGroupManager|\PHPUnit_Framework_MockObject_MockObject */
+	protected $groupManager;
+	/** @var IAppManager|\PHPUnit_Framework_MockObject_MockObject */
+	protected $appManager;
+	/** @var IClientService|\PHPUnit_Framework_MockObject_MockObject */
+	protected $client;
+
+	public function setUp() {
+		parent::setUp();
+
+		$this->config = $this->getMock('OCP\IConfig');
+		$this->notificationManager = $this->getMock('OCP\Notification\IManager');
+		$this->groupManager = $this->getMock('OCP\IGroupManager');
+		$this->appManager = $this->getMock('OCP\App\IAppManager');
+		$this->client = $this->getMock('OCP\Http\Client\IClientService');
+	}
+
+	/**
+	 * @param array $methods
+	 * @return BackgroundJob|\PHPUnit_Framework_MockObject_MockObject
+	 */
+	protected function getJob(array $methods = []) {
+		if (empty($methods)) {
+			return new BackgroundJob(
+				$this->config,
+				$this->notificationManager,
+				$this->groupManager,
+				$this->appManager,
+				$this->client
+			);
+		} {
+			return $this->getMockBuilder('OCA\UpdateNotification\Notification\BackgroundJob')
+				->setConstructorArgs([
+					$this->config,
+					$this->notificationManager,
+					$this->groupManager,
+					$this->appManager,
+					$this->client,
+				])
+				->setMethods($methods)
+				->getMock();
+		}
+	}
+
+	public function testRun() {
+		$job = $this->getJob([
+			'checkCoreUpdate',
+			'checkAppUpdates',
+		]);
+
+		$job->expects($this->once())
+			->method('checkCoreUpdate');
+		$job->expects($this->once())
+			->method('checkAppUpdates');
+
+		$this->invokePrivate($job, 'run', [null]);
+	}
+
+	public function dataCheckCoreUpdate() {
+		return [
+			['daily', null, null],
+			['git', null, null],
+			['beta', false, null],
+			['beta', [
+				'version' => '9.2.0',
+			], '9.2.0'],
+			['stable', false, null],
+			['stable', [
+				'version' => '9.2.0',
+			], '9.2.0'],
+			['production', false, null],
+			['production', [
+				'version' => '9.2.0',
+			], '9.2.0'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataCheckCoreUpdate
+	 *
+	 * @param string $channel
+	 * @param mixed $versionCheck
+	 * @param null|string $notification
+	 */
+	public function testCheckCoreUpdate($channel, $versionCheck, $notification) {
+		$job = $this->getJob([
+			'getChannel',
+			'createVersionCheck',
+			'createNotifications',
+		]);
+
+		$job->expects($this->once())
+			->method('getChannel')
+			->willReturn($channel);
+		
+		if ($versionCheck === null) {
+			$job->expects($this->never())
+				->method('createVersionCheck');
+		} else {
+			$check = $this->getMockBuilder('OC\Updater\VersionCheck')
+				->disableOriginalConstructor()
+				->getMock();
+			$check->expects($this->once())
+				->method('check')
+				->willReturn($versionCheck);
+
+			$job->expects($this->once())
+				->method('createVersionCheck')
+				->willReturn($check);
+		}
+
+		if ($notification === null) {
+			$job->expects($this->never())
+				->method('createNotifications');
+		} else {
+			$job->expects($this->once())
+				->method('createNotifications')
+				->willReturn('core', $notification);
+		}
+
+		$this->invokePrivate($job, 'checkCoreUpdate');
+	}
+
+	public function dataCheckAppUpdates() {
+		return [
+			[
+				['app1', 'app2'],
+				[
+					['app1', false],
+					['app2', '1.9.2'],
+				],
+				[
+					['app2', '1.9.2'],
+				],
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataCheckAppUpdates
+	 *
+	 * @param string[] $apps
+	 * @param array $isUpdateAvailable
+	 * @param array $notifications
+	 */
+	public function testCheckAppUpdates(array $apps, array $isUpdateAvailable, array $notifications) {
+		$job = $this->getJob([
+			'isUpdateAvailable',
+			'createNotifications',
+		]);
+
+		$this->appManager->expects($this->once())
+			->method('getInstalledApps')
+			->willReturn($apps);
+
+		$job->expects($this->exactly(sizeof($apps)))
+			->method('isUpdateAvailable')
+			->willReturnMap($isUpdateAvailable);
+
+		$mockedMethod = $job->expects($this->exactly(sizeof($notifications)))
+			->method('createNotifications');
+		call_user_func_array([$mockedMethod, 'withConsecutive'], $notifications);
+
+		$this->invokePrivate($job, 'checkAppUpdates');
+	}
+
+	public function dataCreateNotifications() {
+		return [
+			['app1', '1.0.0', '1.0.0', false, false, null, null],
+			['app2', '1.0.1', '1.0.0', '1.0.0', true, ['user1'], [['user1']]],
+			['app3', '1.0.1', false, false, true, ['user2', 'user3'], [['user2'], ['user3']]],
+		];
+	}
+
+	/**
+	 * @dataProvider dataCreateNotifications
+	 *
+	 * @param string $app
+	 * @param string $version
+	 * @param string|false $lastNotification
+	 * @param string|false $callDelete
+	 * @param bool $createNotification
+	 * @param string[]|null $users
+	 * @param array|null $userNotifications
+	 */
+	public function testCreateNotifications($app, $version, $lastNotification, $callDelete, $createNotification, $users, $userNotifications) {
+		$job = $this->getJob([
+			'deleteOutdatedNotifications',
+			'getUsersToNotify',
+		]);
+
+		$this->config->expects($this->once())
+			->method('getAppValue')
+			->with('updatenotification', $app, false)
+			->willReturn($lastNotification);
+
+		if ($lastNotification !== $version) {
+			$this->config->expects($this->once())
+				->method('setAppValue')
+				->with('updatenotification', $app, $version);
+		}
+
+		if ($callDelete === false) {
+			$job->expects($this->never())
+				->method('deleteOutdatedNotifications');
+		} else {
+			$job->expects($this->once())
+				->method('deleteOutdatedNotifications')
+				->with($app, $callDelete);
+		}
+
+		if ($users === null) {
+			$job->expects($this->never())
+				->method('getUsersToNotify');
+		} else {
+			$job->expects($this->once())
+				->method('getUsersToNotify')
+				->willReturn($users);
+		}
+
+		if ($createNotification) {
+			$notification = $this->getMock('OCP\Notification\INotification');
+			$notification->expects($this->once())
+				->method('setApp')
+				->with('updatenotification')
+				->willReturnSelf();
+			$notification->expects($this->once())
+				->method('setDateTime')
+				->willReturnSelf();
+			$notification->expects($this->once())
+				->method('setObject')
+				->with($app, $version)
+				->willReturnSelf();
+			$notification->expects($this->once())
+				->method('setSubject')
+				->with('update_available')
+				->willReturnSelf();
+
+			if ($userNotifications !== null) {
+				$mockedMethod = $notification->expects($this->exactly(sizeof($userNotifications)))
+					->method('setUser')
+					->willReturnSelf();
+				call_user_func_array([$mockedMethod, 'withConsecutive'], $userNotifications);
+
+				$this->notificationManager->expects($this->exactly(sizeof($userNotifications)))
+					->method('notify')
+					->willReturn($notification);
+			}
+
+			$this->notificationManager->expects($this->once())
+				->method('createNotification')
+				->willReturn($notification);
+		} else {
+			$this->notificationManager->expects($this->never())
+				->method('createNotification');
+		}
+
+		$this->invokePrivate($job, 'createNotifications', [$app, $version]);
+	}
+
+	public function dataGetUsersToNotify() {
+		return [
+			[['g1', 'g2'], ['g1' => null, 'g2' => ['u1', 'u2']], ['u1', 'u2']],
+			[['g3', 'g4'], ['g3' => ['u1', 'u2'], 'g4' => ['u2', 'u3']], ['u1', 'u2', 'u3']],
+		];
+	}
+
+	/**
+	 * @dataProvider dataGetUsersToNotify
+	 * @param string[] $groups
+	 * @param array $groupUsers
+	 * @param string[] $expected
+	 */
+	public function testGetUsersToNotify($groups, array $groupUsers, array $expected) {
+		$job = $this->getJob();
+
+		$this->config->expects($this->once())
+			->method('getAppValue')
+			->with('updatenotification', 'notify_groups', '["admin"]')
+			->willReturn(json_encode($groups));
+
+		$groupMap = [];
+		foreach ($groupUsers as $gid => $uids) {
+			if ($uids === null) {
+				$group = null;
+			} else {
+				$group = $this->getGroup($gid);
+				$group->expects($this->any())
+					->method('getUsers')
+					->willReturn($this->getUsers($uids));
+			}
+			$groupMap[] = [$gid, $group];
+		}
+		$this->groupManager->expects($this->exactly(sizeof($groups)))
+			->method('get')
+			->willReturnMap($groupMap);
+
+		$result = $this->invokePrivate($job, 'getUsersToNotify');
+		$this->assertEquals($expected, $result);
+
+		// Test caching
+		$result = $this->invokePrivate($job, 'getUsersToNotify');
+		$this->assertEquals($expected, $result);
+	}
+
+	public function dataDeleteOutdatedNotifications() {
+		return [
+			['app1', '1.1.0'],
+			['app2', '1.2.0'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataDeleteOutdatedNotifications
+	 * @param string $app
+	 * @param string $version
+	 */
+	public function testDeleteOutdatedNotifications($app, $version) {
+		$notification = $this->getMock('OCP\Notification\INotification');
+		$notification->expects($this->once())
+			->method('setApp')
+			->with('updatenotification')
+			->willReturnSelf();
+		$notification->expects($this->once())
+			->method('setObject')
+			->with($app, $version)
+			->willReturnSelf();
+
+		$this->notificationManager->expects($this->once())
+			->method('createNotification')
+			->willReturn($notification);
+		$this->notificationManager->expects($this->once())
+			->method('markProcessed')
+			->with($notification);
+
+		$job = $this->getJob();
+		$this->invokePrivate($job, 'deleteOutdatedNotifications', [$app, $version]);
+	}
+
+	/**
+	 * @param string[] $userIds
+	 * @return IUser[]|\PHPUnit_Framework_MockObject_MockObject[]
+	 */
+	protected function getUsers(array $userIds) {
+		$users = [];
+		foreach ($userIds as $uid) {
+			$user = $this->getMock('OCP\IUser');
+			$user->expects($this->any())
+				->method('getUID')
+				->willReturn($uid);
+			$users[] = $user;
+		}
+		return $users;
+	}
+
+	/**
+	 * @param $gid
+	 * @return \OCP\IGroup|\PHPUnit_Framework_MockObject_MockObject
+	 */
+	protected function getGroup($gid) {
+		$group = $this->getMock('OCP\IGroup');
+		$group->expects($this->any())
+			->method('getGID')
+			->willReturn($gid);
+		return $group;
+	}
+}