Unterminated character class using square brackets

Question

I'm pulling in a web data source and need to clean it up. In Pebble JS I've used the following which works on a standard web page:

    var arr = JSON.parse('[' + str.replace(/\]\[/gi, '],[') + ']');
    console.log(arr);

This returns the error 'Unterminated character class'. I've tried various methods of escaping the characters but no success.