CoffeeScript compatibility problem

[jorgebg]

The following code works in CoffeeScript:

Express = require 'express'
class MyApp extends Express
myapp = new MyApp
myapp.listen 3000

According to CoffeeScript to LiveScript Conversion Guide, the following code should work in LiveScript, but it throws the following error:

TypeError: Object #<MyApp> has no method 'listen'
    at Object.<anonymous> (/tmp/myapp.coffee:11:7)
 7|   }
 8|   return MyApp;
 9| }(Express));
10| myapp = new MyApp;
11+ myapp.listen(3000);
12| function extend$(sub, sup){
13|   function fun(){} fun.prototype = (sub.superclass = sup).prototype;
14|   (sub.prototype = new fun).constructor = sub;
15|   if (typeof sup.extended == 'function') sup.extended(sub);
    at Module._compile (module.js:449:26)
    at Object.module.exports.LiveScript.run (/usr/local/lib/node_modules/LiveScript/lib/node.js:21:19)
    at compileScript (/usr/local/lib/node_modules/LiveScript/lib/command.js:181:29)
    at /usr/local/lib/node_modules/LiveScript/lib/command.js:110:9
    at /usr/local/lib/node_modules/LiveScript/lib/command.js:100:5
    at fs.readFile (fs.js:176:14)
    at Object.oncomplete (fs.js:297:15)

Why? And how can it be solved? Thanks!

PD: In case you doubt about what express is, it is the well-known web application framework for node :) and here is the link: http://expressjs.com/

[vendethiel]

EDIT : I remembered this not working but apparently it does

[jorgebg]

Yes it works in CoffeeScript :(

[gkz]

Can you log the myapp object and check out what's up with it - what its prototype is, etc.?

[vendethiel]

Isn't it because we don't actually return the parent constructor ? Other typed thingies

[jorgebg]

Yes it is, If I return the parent constructor it works:

Express = require 'express'
class MyApp extends Express
  -> return super ...
myapp = new MyApp
myapp.listen 3000

But when I try to extend it without overriding the constructor in order to return the parent constructor, the TypeError appears again:

class MyApp2 extends MyApp
myapp2 = new MyApp2
myapp2.listen 3000

TypeError: Object #<MyApp2> has no method 'listen'
    at Object.<anonymous> (/tmp/myapp2.ls:19:8)
...

Some logging:

Express = require 'express'
class MyApp extends Express
console.log MyApp # Too long, pasted here http://pastebin.com/fwM33jXP 
myapp = new MyApp
cosole.log myapp # It returns an empty object {}