module pattern with require

1. ExampleProto.js

function construct(ctor) {
  function P(args) { return ctor.apply(this, args) }
  P.prototype = ctor.prototype
  return function create(args) {
    return new P(args)
  }
}

module.exports = ExampleProto
function ExampleProto() {
  if (!(this instanceof ExampleProto)) return ExampleProto.prototype.create(arguments)
  this.arguments = Array.prototype.slice.call(arguments)
}

ExampleProto.prototype.create = construct(ExampleProto)

ExampleProto.prototype.pub = function () {
  return 'public'
}

function priv() {
  return 'private'
}

ExampleProto.prototype.callPriv = function () {
  return priv()
}

2. index.js

var ExampleProto = require('./ExampleProto')

console.log('can be called with new:', (new ExampleProto) instanceof ExampleProto)
console.log('can be called as a function:', ExampleProto() instanceof ExampleProto)

3. evaluated index.js

var ExampleProto = (function () {
  function construct(ctor) {
    function P(args) { return ctor.apply(this, args) }
    P.prototype = ctor.prototype
    return function create(args) {
      return new P(args)
    }
  }
  
  function ExampleProto() {
    if (!(this instanceof ExampleProto)) return ExampleProto.prototype.create(arguments)
    this.arguments = Array.prototype.slice.call(arguments)
  }
  
  ExampleProto.prototype.create = construct(ExampleProto)
  
  ExampleProto.prototype.pub = function () {
    return 'public'
  }
  
  function priv() {
    return 'private'
  }
  
  ExampleProto.prototype.callPriv = function () {
    return priv()
  }

  return ExampleProto
})()

console.log('can be called with new:', (new ExampleProto) instanceof ExampleProto)
console.log('can be called as a function:', ExampleProto() instanceof ExampleProto)

4. index.coffee

class ExampleProto
  construct = (ctor) ->
    P = (args) ->
      ctor.apply @, args
    P:: = ctor::
    create = (args) ->
      new P(args)

  create: construct(ExampleProto)

  constructor: (args...) ->
    return ExampleProto::create(args) unless @ instanceof ExampleProto
    @arguments = args

  priv = ->
    "private"

  pub: ->
    "public"

  callPriv: ->
    priv()

console.log 'can be called with new:', (new ExampleProto) instanceof ExampleProto
console.log 'can be called as a function:', ExampleProto() instanceof ExampleProto