Parse ill formed JSON string

Question

I am being sent an ill formed JSON string from a third party. I tried using JSON.parse(str) to parse it into a JavaScript object but it of course failed.

The reason being is that the keys are not strings:

{min: 100}

As opposed to valid JSON string (which parses just fine):

{"min": 100}

I need to accept the ill formed string for now. I imagine forgetting to properly quote keys is a common mistake. Is there a good way to change this to a valid JSON string so that I can parse it? For now I may have to parse character by character and try and form an object, which sounds awful.

Ideas?

Answer 1

You could just eval, but that would be bad security practice if you don't trust the source. Better solution would be to either modify the string manually to quote the keys or use a tool someone else has written that does this for you (check out https://github.com/daepark/JSOL written by daepark).

Answer 2

I did this just recently, using Uglifyjs to evaluate:

var jsp = require("uglify-js").parser;
var pro = require("uglify-js").uglify;

var orig_code = "var myobject = " + badJSONobject;
var ast = jsp.parse(orig_code); // parse code and get the initial AST
var final_code = pro.gen_code(ast); // regenerate code

$('head').append('<script>' + final_code + '; console.log(JSON.stringify(myobject));</script>');

This is really sloppy in a way, and has all the same problems as an eval() based solution, but if you just need to parse/reformat the data one time, then the above should get you a clean JSON copy of the JS object.