Serialize references

serialize.js

function randomID() {
  return Math.random();
}

function serialize(obj, store) {
  const retVal = {};
  
  store = store || {
    root: retVal,
    objects: {},
    objectIdMap: new Map()
  };
  
  const myId = randomID();
  store.objects[myId] = retVal;
  store.objectIdMap.set(obj, myId);
  
  Object.keys(obj).forEach(key => {
    if (typeof obj[key] === "object") {
      let id = store.objectIdMap.get(obj[key]);
      
      if (!id) {
        id = randomID();
        serialize(obj[key], store);
      }
      retVal[key] = "ref_" + id;
    } else if (typeof obj[key] === "string") {
      retVal[key] = "string_" + obj[key];
    } else {
      retVal[key] = obj[key];
    }
  });
  
  return { object: retVal, store };
}

const myobj = {};
const foo = { key: 5, ref2: myobj };
myobj.circular = foo;
const bar = { ref: foo, num: 3, str: "test" };
const serialized = serialize(bar);
console.log(JSON.stringify({
  root: serialized.store.root,
  objects: serialized.store.objects })
);