Using CoffeeScript 1.6.3 (rev 581af4540ac).

surprise.coffee

Q = require 'q'

value = if this.require 'aa' else 'bb'  # missing `then` in `if` expr; should be compile error

incorrectChain = Q.nfcall(fun).then(
    (result) -> console.log 'Result', result
    , (error) -> console.error 'Error', error  # a small indentation error
  )

fun = (callback) -> callback(new Error('intentional error'))

surprise.js

// Generated by CoffeeScript 1.6.3
(function() {
  var Q, fun, incorrectChain, value;

  Q = require('q');

  value = this.require('aa') ? void 0 : 'bb';

  incorrectChain = Q.nfcall(fun).then(function(result) {
    return console.log('Result', result, function(error) {
      return console.error('Error', error);
    });
  });

  fun = function(callback) {
    return callback(new Error('intentional error'));
  };

}).call(this);