ES5 class inherits from ES6 class (with proxy)

by Arnaud Buchholz

JavaScript

window.onerror = e => alert(e)

class A {
  constructor () {
    this._a = "A"
  }
}

class B extends A {
  constructor (param) {
    super()
    this._b = "B"
    this._param = param
  }
}

alert(B.toString())

function constructorOfC (param2) {
  this.$super("test")
  this._c = "C"
  this._param2 = param2
}

const C = (function () {
  function C () {
    let instance
    const $super = function () {
        instance = Reflect.construct(B, arguments, C)
    }
    const proxy = new Proxy({}, {
    	get: function (obj, property) {
        if (property === '$super') {
          return $super
        }
        return instance[property]
      },
      set: function (obj, property, value) {
        instance[property] = value
      }
    })
    constructorOfC.apply(proxy, arguments)
    return instance
  }
  C.prototype = Object.create(B.prototype)
  return C
}())

var c = new C("test2");

alert([
  "OK",
  "_a: " + c._a,
  "is A: " + (c instanceof A),
  "_b: " + c._b,
  "is B: " + (c instanceof B),
  "_c: " + c._c,
  "is C: " + (c instanceof C),
  "_param: " + c._param,
  "_param2: " + c._param2
].join("\n\t"))