Promise Rejection in Controller

//System.Api
function getData(url, params) {
  return $http({
    method: 'GET',
    url: url,
    params: params
  });
}

//Some user service
function getDataForUser(userId) {
  var params = {userId: userId};
  return getData('/user', params);
}

//Some user controller
User.getDataForUser(userId).then(userSuccessHandler, userErrorHandler);