Sinon useFakeTimers and Ember

gistfile1.js

test('creates a local creation time property when saving', function () {
  expect(1);

  var now = new Date().getTime(),
      clock = sinon.useFakeTimers(now),
      model = App.Model.create(),
      promise = Em.RSVP.resolve(),
      superStub = sinon.stub(model, '_super').returns(promise);

  model.save().then(function () {
    equal(model.get('locallyCreated'), now, 'the models locallyCreated property is the current timestamp');
  });

  // RSVP uses setTimeout to mimic async promises, but the sinon fake clock stubs setTimeout. Thus, tick forward a
  // millisecond to force the async promise to resolve.
  clock.tick(1);

  superStub.restore();
  clock.restore();
});