Fix test_directory_map

See #2475 and point 2 of #2334
diff --git a/tests/codeigniter/helpers/directory_helper_test.php b/tests/codeigniter/helpers/directory_helper_test.php
index 41370e6..214ad2c 100644
--- a/tests/codeigniter/helpers/directory_helper_test.php
+++ b/tests/codeigniter/helpers/directory_helper_test.php
@@ -14,6 +14,8 @@
 
 	public function test_directory_map()
 	{
+		$ds = DIRECTORY_SEPARATOR;
+
 		$structure = array(
 			'libraries' => array(
 				'benchmark.html' => '',
@@ -28,9 +30,9 @@
 
 		// test default recursive behavior
 		$expected = array(
-			'libraries/' => array(
+			'libraries'.$ds => array(
 				'benchmark.html',
-				'database/' => array('active_record.html', 'binds.html'),
+				'database'.$ds => array('active_record.html', 'binds.html'),
 				'email.html',
 				'0'
 			)
@@ -39,12 +41,12 @@
 		$this->assertEquals($expected, directory_map(vfsStream::url('testDir')));
 
 		// test detection of hidden files
-		$expected['libraries/'][] = '.hiddenfile.txt';
+		$expected['libraries'.$ds][] = '.hiddenfile.txt';
 
 		$this->assertEquals($expected, directory_map(vfsStream::url('testDir'), FALSE, TRUE));
 
 		// test recursion depth behavior
-		$this->assertEquals(array('libraries/'), directory_map(vfsStream::url('testDir'), 1));
+		$this->assertEquals(array('libraries'.$ds), directory_map(vfsStream::url('testDir'), 1));
 	}
 
 }