Using Q, is this the best way to pass the results of two sequenced promises to the subsequent `then`/`spread` clause?

CombiningSequencedPromiseResultsWithQ.js

'use strict';

var Q = require('q');
var cmd = new require('commander').Command();
var client = new require('myAwesomeApi').Client();

var getUsername = function(done) {
  var username;
  cmd.prompt('Username: ', function(name) {
    if (!name) {
      done(new Error('You must provide a username!'));
    }
    else {
      done(null, username);
    }
  });
};

var getPassword = function(done) {
  cmd.password('Password: ', '*', function(pass) {
    if (!pass) {
      done(new Error('You must provide a password!'));
    }
    else {
      process.stdin.destroy();
      done(null, pass);
    }
  });
};

Q.napply(getUsername, null, []).then(function(username) {
  return Q.napply(getPassword, null, []).then(function(password) {
    return Q.resolve([username, password]);
  });
}).spread(function(username, password) {
  return Q.napply(client.login, client, [username, password]);
})

Cool, I'll go with catch (definitely prefer its obviously semantic name over fail) and an empty done. Thanks again!