Manual:Jsparse.php/en

Details
jsparse.php file is a maintenance script for testing JavaScript validity parses using JSMin+'s parser. This is a useful feature to run parsing/syntax check on JavaScript files.

Options/Arguments
This takes file(s) as their first argument which you want to validate.

Common error
It comes when the file does not exist or the user running the script does not have permission to read the file.
 * $filename ERROR: could not read file

In case file does exist, check file permission. If you are root user then you can run script with sudo.