Single line comment does deactivate syntax highlighting (php)

[sanjinso]

Environment info

• OS: Win10
• App Version (Command/Ctrl + ,): 1.9.1

Description of the problem / feature request / question:

A single line comment does deactivate .php syntax highlighting in preview view. (Editor is fine)

If possible, provide a sample gist or screenshot:

SYNTAX HIGHLIGHTING DOES NOT WORK;

function wpse_custom_menu_order( $menu_ord ) {
return array(
'index.php' //test
);
}

SYNTAX HIGHLIGHTING DOES WORK;

function wpse_custom_menu_order( $menu_ord ) {
return array(
'index.php'
);
}