Mixin.js

var Mixin = {}

Mixin.mix_into_prototype = function() {
    for (var i = 0; i < arguments.length; i++) {
      let current_object = arguments[i]
      for (let key in current_object) {
        this[key] = current_object[key]
      }
    }
    return this;
}
// by using mixin as the __proto__ at the first time
// by using the caller as the __proto__ in the future
Mixin.create_prototype = function () {
    let is_create_with_no_object = (arguments.length == 0)
    if (is_create_with_no_object) {
      return Object.create(this) // return an instance of mixin
    } else {
      let an_empty_object_inherit_caller = Object.create(this)
      let other_objects_to_mixin = arguments
      return this.mix_into_prototype.apply(an_empty_object_inherit_caller, other_objects_to_mixin)
    }
}

// by using the caller as the __proto__ in the future
Mixin.generate_constructor = function () {
    let an_empty_object_inherit_caller = Object.create(this)
    let other_objects_to_mixin = arguments
    let mixined_Mixin_instance = Mixin.mix_into_prototype.apply(an_empty_object_inherit_caller, other_objects_to_mixin)
    let Klass = mixined_Mixin_instance.constructor
    Klass.prototype = mixined_Mixin_instance;
    return Klass;
}

let a = {
  constructor: function Set_constructor (name, age) {
      this.name = name;
      this.age = age;
  },
  toString: function albert(){return 'albert'},
  proto_name: 'albert',
  proto_age: 12
}

let b = {
  salary: 12,
  dept: 'hr'
}

let d = {
  aaa: 12,
  debbbpt: 'hr'
}

let cls = Mixin.generate_constructor(a, b);
// function cls (name, age){// a.constructor
//   this.name = 'name';
//   this.age = age;
// }
// cls.prototype = {
//   constructor: cls
//   __proto__: caller of generate_constructor
//   ...a
//   ...b
// }
// // an_empty_object_inherit_caller
// // then mixin a and b


let c = new cls('c', 11);
// {
//   name: 'al',
//   age: 12,
//   __proto__: cls.prototype // c.__proto__.__proto__ = Mixin
// }

let e = c.create_prototype(d)
// {
//   constructor: c.constructor
//   __proto__: c
//   ..d
// }
let f = e.generate_constructor()
// function f (name, age){ // a.constructor
//   this.name = 'name';
//   this.age = age;
// }
// f.prototype = {
//   constructor: f
//   __proto__: e
//   ..d
// }
// // an_empty_object_inherit_caller
// // then mixin a and b
let g = new f('g', 11111) // g.__proto__ = f.prototype
console.log(g.__proto__.__proto__.__proto__.__proto__)
exports.Mixin = Mixin;