composition-example-2.js

const canBark = (state, howManyTimes) => {
  state.barks += howManyTimes
}

const canEat = (state, howMuch) => {
  state.food -= howMuch
}

const dog = (name) => {
  let state = {
    name,
    barks: 0,
    food: 100,
  }
  return Object.assign(state, {
    bark: (...args) => canBark(state, ...args),
    eat: (...args) => canEat(state, ...args)
  })
}

const alfie = dog('Alfie')
alfie.bark(3)
alfie.eat(6)
console.log(alfie.barks) //3
console.log(alfie.food) //94