Users of my Settings sync extension having problems shanalikhan/code-settings-sync#190

When they have trailing commas in settings.json , API doenst allow extension to add keys and values in settings.json file , Giving error code 4.

There should be way in code to let users know that they dont have valid JSON in settings.json file e.g trailing commas, without opening that file may be in status bar or let API to add settings in the settings.json file even it have trailing commas.