Record Object

var nextId = 1
var idToEntry = new Map()
var objectToId = new Map()

function record(obj) {
  if (obj === null) {
    return {
      type: "null"
    }
  }
  
  switch (typeof obj) {
    case "string":
    case "number":
    case "boolean":
      return {
        type: typeof obj,
        value: obj
      }
    case "undefined":
      return {
        type: "undefined"
      }
    default:
  }
  
  let id = objectToId.get(obj)
  if (id === undefined) {
    id = nextId++
    const entry = { id: id }
    objectToId.set(obj, id)
    
    const entries = []
    for (const prop of Object.getOwnPropertyNames(obj)) {
      const desc = Object.getOwnPropertyDescriptor(obj, prop)
      if (desc["value"] !== undefined) {
        entries.push({
          name: prop,
          value: record(desc.value),
          writable: desc.writable,
          configurable: desc.configurable,
          enumerable: desc.enumerable
        })
      } else {
        entries.push({
          name: prop,
          "get": record(desc.get),
          "set": record(desc.set),
          configurable: desc.configurable,
          enumerable: desc.enumerable
        })
      }
    }
    idToEntry.set(id, entries)
  }
  
  return {
    type: "ref",
    target: id
  }
}

var me = {
  test: 3
}

me.me = me
Object.freeze(me)

record(me)


for (const [,entry] of idToEntry) {
  console.log(entry)
}