machine.js

function CoffeeMachine(power, capacity) {
  Machine.apply(this, arguments);
  let waterAmount;
  const WATER_HEAT_CAPACITY = 4200;
  let timerId;
  console.log('Create coffee machine with capacity of ' + power + ' vt');
  this.setWaterAmount = function (amount) {
    if (amount < 0) throw new Error('The number must be positive');
    if (amount > capacity) throw new Error('Do not add more water then ' + capacity);

    waterAmount = amount;
  }
  let getBoilTime = function () {
    return this.waterAmount * WATER_HEAT_CAPACITY * 80 / power;
  }.bind(this);
  function onReady() {
    console.log('Coffee is ready');

  }
  this.setOnReady = function (newReady) {
    onReady = newReady;
  }
  this.getPower = function () {
    return console.log('Power of coffee machine -' + power)
  }
  this.getWaterAmount = function (amount) {
    return waterAmount;
  };
  this.run = function () {

    timerId = setTimeout(function () {
      onReady();
    }, getBoilTime())
  }
  this.stop = function () {
    clearTimeout(timerId);
  }
  this.addWater = function (water) {
    this.setWaterAmount(waterAmount + water);
  }
  let parentEnable = this.enable;
  this.enable = function () {
    parentEnable();
    console.log('coffee machine enabled')

  }
}
function Machine(power) {
  this._power = power
  this._enabled = false;
  let self = this;
  this.enable = function () {
    this._enabled = true;
    console.log(true);
  }
  this.disable = function () {
    this._enabled = false;
  }
}
let machine = new Machine(120000);
let coffeeMachine = new CoffeeMachine(100000, 400);

coffeeMachine.setWaterAmount(300);
coffeeMachine.run();
coffeeMachine.setOnReady(function () {
  var amount = coffeeMachine.getWaterAmount();
  console.log('Готов кофе: ' + amount + 'мл');
});
coffeeMachine.enable();
machine.enable();