try json5 https://github.com/aseemk/json5

convert.sh

node_modules/json5/lib/cli.js -c data.json5
cat data.json
{
    "foo": "bar",
    "while": true,
    "this": "is a multi-line string",
    "here": "is another",
    "hex": 3735928559,
    "half": 0.5,
    "delta": 10,
    "to": null,
    "finally": "a trailing comma",
    "oh": [
        "we shouldn't forget",
        "arrays can have",
        "trailing commas too"
    ]
}%           

data.json5

{
    foo: 'bar',
    while: true,

    this: 'is a \
multi-line string',

    // this is an inline comment
    here: 'is another', // inline comment

    /* this is a block comment
       that continues on another line */

    hex: 0xDEADbeef,
    half: .5,
    delta: +10,
    to: Infinity,   // and beyond!

    finally: 'a trailing comma',
    oh: [
        "we shouldn't forget",
        'arrays can have',
        'trailing commas too',
    ],
}

json5.js

// json5 をrequireできるようにする
require('json5/lib/require');
var JSON5 = require('json5');
var data = require('./data');
result = JSON5.stringify(data);
console.log(result);

parser.sh

node json5.js
{foo:"bar",while:true,this:"is a multi-line string",here:"is another",hex:3735928559,half:0.5,delta:10,to:null,finally:"a trailing comma",oh:["we shouldn't forget","arrays can have","trailing commas too"]}