batched-mutations.js

import assert from 'assert'
import Immutable from 'immutable'

const batchSetters = state => {
  state.set('a', 1)
  state.set('b', 2)
  state.set('c', 3)

  return state
}

const immutableState = () => Immutable.fromJS({ a: 0, b: 0, c: 0 })

const normal = batchSetters(immutableState())
const batched = immutableState().withMutations(batchSetters)
const expected = { a: 1, b: 2, c: 3 }

assert.equal(normal.toJS(), expected, 'normal')
assert.equal(batched.toJS(), expected, 'batched')