🦖 Duno - First attempt to create an Immutable lib with easy API

index.js

function duno(root, diff, index) {
  let dunoed = Object.assign({}, root)

  for (let key in diff) {
    switch (typeof diff[key]) {
      case 'function':
        dunoed[key] = diff[key](dunoed[key], dunoed)
        break
      default:
        dunoed[key] = diff[key]
        break
    }
  }

  return dunoed
}

let state = {
  entities: {
    abc: {
      id: 'abc',
      pseudo: 'abc'
    },
    def: {
      id: 'def',
      pseudo: 'def'
    }
  },
  result: ['abc', 'def']
}

let dunoed

// edit a key in a 2 depth deep object
dunoed = duno(state, {
  entities: self => duno(self, {
    abc: self => duno(self, {
      pseudo: 'lol'
    })
  })
})

console.log(dunoed)

// edit a key in a 2 depth deep object (advanced)
dunoed = duno(state, {
  entities: self => duno(self, {
    abc: (self, root) => duno(root.abc, {
      pseudo: 'lol'
    })
  })
})

console.log(dunoed)

// delete an entry
dunoed = duno(state, {
  entities: self => Object
    .keys(self)
    .filter(key => key !== 'abc')
    .reduce((obj, key) => Object.assign(obj, { [key]: self[key] }), {}),
  result: self => self.filter(value => value !== 'abc')
})

console.log(dunoed)

// replace a key in an 1 depth deep object and a value in an array
dunoed = duno(state, {
  entities: self => Object
    .keys(self)
    .filter(key => key !== 'abc')
    .concat(['ghi'])
    .reduce((obj, key) => Object.assign(obj, { [key]:
      key === 'ghi' ? Object.assign(self.abc, { id: 'ghi' }) : self[key]
    }), {}),
  result: self => self.map(value => value === 'abc' ? 'ghi' : value)
})

console.log(dunoed)