Versioned Proxy - using proxy to increment a version on object mutation

versioned-proxy.js

export const $version = Symbol('version')

const VersionedProxy = {
  set(target, prop, value) {
    target[$version] = target[$version] + 1
    target[prop] = value
  },

  deleteProperty(target, prop) {
    target[$version] = target[$version] + 1
    delete target[prop]
  }
}

export const versioned = target => {
  target[$version] = 0
  return new Proxy(target, VersionedProxy)
}