mosaic/src/proxy.js

import { typeOf } from "./helpers.js"

export const proxy = (root, callback) => {
  let proxyCache = new WeakMap()

  function createProxy(target, handler) {
    let proxy = proxyCache.get(target)
    if (proxy === undefined) {
      proxy = new Proxy(target, handler)
      proxyCache.set(target, proxy)
    }
    return proxy
  }

  const handler = {
    get(target, property) {
      if (["Object", "Array"].includes(typeOf(target[property]))) {
        return createProxy(target[property], handler)
      } else {
        return Reflect.get(...arguments)
      }
    },
    set(target, property, value) {
      if (value === target[property]) return true

      callback()
      return Reflect.set(...arguments)
    },
    deleteProperty() {
      callback()
      return Reflect.deleteProperty(...arguments)
    },
  }

  return new Proxy(root, handler)
}