Proxy wrapper for objects that tracks changes in a "draft" object without touching the underlying initial object

proxy.js

const getProxyExample = (initialObject = {}) => {
  const buildProxyClosure = () => {
      let data = {};
      let proxyHandler = {
          get(obj, prop) {
              return prop in data ? data[prop] : obj[prop];
          },
          set(obj, prop, value) {
              data[prop] = value;
          }
      };
      let getDraftData = () => { return {...data} };

      return [getDraftData, proxyHandler];
  }

  let [getDraftData, proxyHandler] = buildProxyClosure();
  let initialObjectCopy = { ...initialObject };
  let getInitialData = () => initialObjectCopy;
  let getMergedObject = () => {
    return { ...getInitialData(), ...getDraftData() };
  };

  let proxyExample = new Proxy(initialObjectCopy, proxyHandler);
  return {proxyExample, getDraftData, getInitialData, getMergedObject}
}

const {proxyExample, getDraftData, getInitialData, getMergedObject} = getProxyExample();