im-object.js

var counter = 0;
var ticks = 0;

setImmediate(function countTick() {
  ticks++

  setImmediate(countTick)
})

var todo = new ImObject({
  title: "foo",
  completed: false
}, function onChange(todo2) {
  counter++
  assert.equal(counter, 1)
  assert.equal(ticks, 1)
  assert.equal(todo2.title, "bar")
  assert.equal(todo2.completed, true)

  // if someone mutates todo2 then
  // this onChange listener gets called
  // with todo3 on the next setImmediate
  // all mutations to todo2 are batched in
  // it's tick and emit a new immutable todo3
  // in the next tick
})

todo.title = "bar"
todo.completed = true

assert.equal(todo.title, "foo")
assert.equal(todo.completed, false)