composition over inheritance

composition.js

const canStar = state => ({
  star() {
    state.nbStar++
  }
})

const canFork = state => ({
  fork() {
    state.nbFork++
  }
})

const repository = name => {
  let state = {
    name,
    nbStar: 0,
    nbFork: 0
  }

  return { ...state, ...canStar(state), ...canFork(state) }
}

const gist = name => {
  let state = {
    name,
    nbStar: 0
  }

  return { ...state, ...canStar(state) }
}

// ////////// //
// Playground
// ////////// //

const aRepo = repository("docker")
aRepo.star()
aRepo.star()
aRepo.fork()
console.log(aRepo)
// {
//   name: 'docker',
//   nbStar: 0,
//   nbFork: 0,
//   star: [Function: star],
//   fork: [Function: fork]
// }

const aGist = gist("composition.js")
aGist.star()
console.log(aGist)
// {
//   name: 'composition.js',
//   nbStar: 0,
//   star: [Function: star]
// }