test working with files in subdirectories

tests/lib/files/storage/storage.php

@@ -127,6 +127,16 @@ abstract class Storage extends \PHPUnit_Framework_TestCase {
 		$this->assertFalse($this->instance->is_dir('/folder'));
 		$this->assertFalse($this->instance->is_dir('/folder/sub_a'));
 		$this->assertFalse($this->instance->file_exists('/folder/sub_a/file.txt'));
+
+                // check if it's working inside directories as well
+                $this->instance->mkdir('/folder');
+                $this->instance->file_put_contents('/folder/lorem.txt', $sourceText);
+                $this->assertFalse($this->instance->is_dir('/folder/lorem.txt'));
+                $this->assertEquals($sourceText, $this->instance->file_get_contents('/folder/lorem.txt'), 'data returned from file_get_contents is not equal to the source data');
+                $this->instance->file_put_contents('/folder/lorem.txt', '');
+                $this->assertEquals('', $this->instance->file_get_contents('/folder/lorem.txt'), 'file not emptied');
+                $this->instance->rmdir('/folder');
+                $this->assertFalse($this->instance->file_exists('/folder/lorem.txt'));
 	}
 
 	/**