JSON copy w/ function objects

json-serialize.js

const HDR = '#SOURCE'
const compile = (f) => { try { return eval(f) } catch (e) { return new Error(f) } }
const ser = (_, f) => f instanceof Error ? HDR + f.message : f instanceof Function ? HDR + f.toString() : f
const des = (_, f) => f.indexOf && f.indexOf(0, HDR) ? compile(f.slice(HDR.length)) : f

var o = {
  goodFn: () => 5,
  badFn: new Error('() =>< 6')
}
var o2 = JSON.parse(JSON.stringify(o, ser), des)

console.log(o2)
console.log(o2.goodFn())