promise.js

//using a function-scope `data` variable to save the data
function getData(respondentId) {
  var data={};
  return Respondent.findById(respondentId)
        .then(respondent => {
          data.respondent = respondent;
          return Box.findById(respondent.box_id)
        })
        .then(box => {
          data.box = box
          return User.findById(box.owned_by)
        })
        .then(user => {
			data.user = user;
			return data;})
}

//using bluebird-specific `spread`/implicit `all()`
function getData(respondentId) {
  return Respondent.findById(respondentId)
        .then(respondent => {
          return [respondent,Box.findById(respondent.box_id)];
        })
        .spread(respondent, box => {
          return [respondent,box, User.findById(box.owned_by)];
        })
		.spread(respondent, box, user=>({ user, respondent, box }));
}