Add unit test for quote wrapper size root

tests/lib/files/storage/wrapper/quota.php

@@ -99,4 +99,23 @@ class Quota extends \Test\Files\Storage\Storage {
 		$this->assertEquals('user-space', $meta['wrapper_type']);
 		fclose($stream);
 	}
+
+	public function testSpaceRoot() {
+		$storage = $this->getMockBuilder('\OC\Files\Storage\Local')->disableOriginalConstructor()->getMock();
+		$cache = $this->getMockBuilder('\OC\Files\Cache\Cache')->disableOriginalConstructor()->getMock();
+		$storage->expects($this->once())
+			->method('getCache')
+			->will($this->returnValue($cache));
+		$storage->expects($this->once())
+			->method('free_space')
+			->will($this->returnValue(2048));
+		$cache->expects($this->once())
+			->method('get')
+			->with('files')
+			->will($this->returnValue(array('size' => 50)));
+
+		$instance = new \OC\Files\Storage\Wrapper\Quota(array('storage' => $storage, 'quota' => 1024, 'root' => 'files'));
+
+		$this->assertEquals(1024 - 50, $instance->free_space(''));
+	}
 }