diff --git a/apps/files_external/lib/auth/password/globalauth.php b/apps/files_external/lib/auth/password/globalauth.php
index 0684ba7998..c6faee0610 100644
--- a/apps/files_external/lib/auth/password/globalauth.php
+++ b/apps/files_external/lib/auth/password/globalauth.php
@@ -21,8 +21,6 @@
 
 namespace OCA\Files_External\Lib\Auth\Password;
 
-use OCA\Files_External\Lib\Auth\IUserProvided;
-use OCA\Files_External\Lib\DefinitionParameter;
 use OCA\Files_External\Service\BackendService;
 use OCP\IL10N;
 use OCP\IUser;
diff --git a/apps/files_external/tests/auth/password/globalauth.php b/apps/files_external/tests/auth/password/globalauth.php
new file mode 100644
index 0000000000..912bfd1574
--- /dev/null
+++ b/apps/files_external/tests/auth/password/globalauth.php
@@ -0,0 +1,117 @@
+<?php
+/**
+ * @author Robin Appelman <icewind@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\Files_External\Tests\Auth\Password;
+
+use OCA\Files_External\Lib\Auth\Password\GlobalAuth;
+use OCA\Files_external\Lib\StorageConfig;
+use Test\TestCase;
+
+class GlobalAuthTest extends TestCase {
+	/**
+	 * @var \OCP\IL10N|\PHPUnit_Framework_MockObject_MockObject
+	 */
+	private $l10n;
+
+	/**
+	 * @var \OCP\Security\ICredentialsManager|\PHPUnit_Framework_MockObject_MockObject
+	 */
+	private $credentialsManager;
+
+	/**
+	 * @var GlobalAuth
+	 */
+	private $instance;
+
+	protected function setUp() {
+		parent::setUp();
+		$this->l10n = $this->getMock('\OCP\IL10N');
+		$this->credentialsManager = $this->getMock('\OCP\Security\ICredentialsManager');
+		$this->instance = new GlobalAuth($this->l10n, $this->credentialsManager);
+	}
+
+	private function getStorageConfig($type, $config = []) {
+		/** @var \OCA\Files_External\Lib\StorageConfig|\PHPUnit_Framework_MockObject_MockObject $storageConfig */
+		$storageConfig = $this->getMock('\OCA\Files_External\Lib\StorageConfig');
+		$storageConfig->expects($this->any())
+			->method('getType')
+			->will($this->returnValue($type));
+		$storageConfig->expects($this->any())
+			->method('getBackendOptions')
+			->will($this->returnCallback(function () use (&$config) {
+				return $config;
+			}));
+		$storageConfig->expects($this->any())
+			->method('getBackendOption')
+			->will($this->returnCallback(function ($key) use (&$config) {
+				return $config[$key];
+			}));
+		$storageConfig->expects($this->any())
+			->method('setBackendOption')
+			->will($this->returnCallback(function ($key, $value) use (&$config) {
+				$config[$key] = $value;
+			}));
+
+		return $storageConfig;
+	}
+
+	public function testNoCredentials() {
+		$this->credentialsManager->expects($this->once())
+			->method('retrieve')
+			->will($this->returnValue(null));
+
+		$storage = $this->getStorageConfig(StorageConfig::MOUNT_TYPE_ADMIN);
+
+		$this->instance->manipulateStorageConfig($storage);
+		$this->assertEquals([], $storage->getBackendOptions());
+	}
+
+	public function testSavedCredentials() {
+		$this->credentialsManager->expects($this->once())
+			->method('retrieve')
+			->will($this->returnValue([
+				'user' => 'a',
+				'password' => 'b'
+			]));
+
+		$storage = $this->getStorageConfig(StorageConfig::MOUNT_TYPE_ADMIN);
+
+		$this->instance->manipulateStorageConfig($storage);
+		$this->assertEquals([
+			'user' => 'a',
+			'password' => 'b'
+		], $storage->getBackendOptions());
+	}
+
+	/**
+	 * @expectedException \OCA\Files_External\Lib\InsufficientDataForMeaningfulAnswerException
+	 */
+	public function testNoCredentialsPersonal() {
+		$this->credentialsManager->expects($this->never())
+			->method('retrieve');
+
+		$storage = $this->getStorageConfig(StorageConfig::MOUNT_TYPE_PERSONAl);
+
+		$this->instance->manipulateStorageConfig($storage);
+		$this->assertEquals([], $storage->getBackendOptions());
+	}
+
+}