Building UMD modules with dependencies with Browserify

foo.js

var moment = require('moment');

module.exports = {
  now: function() { return moment().format(); },
  hello: function() { return 'Hello world'; }
};

index.js

var _ = require('lodash');

var foo = require('./foo');

module.exports = function () {
  _.forEach(foo, function(fn, key) {
    console.log(key, fn());
  });
};

Makefile

dist:
	browserify \
		--external lodash \
		--external moment \
		--require ./index.js:robot \
		> bundle.js
	cat umd-head.js bundle.js umd-tail.js > robot.js

robot.js

(function(root, factory) {
  if(typeof exports === 'object') {
    module.exports = factory(require('lodash'), require('moment'));
  }
  else if(typeof define === 'function' && define.amd) {
    define(['lodash', 'moment'], factory);
  }
  else {
    root.robot = factory(root._, root.moment);
  }
}(this, function(_, moment) {
  var require = function(name) {
    return {'G2vsx1': _, 'ZCrjYp': moment}[name];
  };

require=(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);throw new Error("Cannot find module '"+o+"'")}var f=n[o]={exports:{}};t[o][0].call(f.exports,function(e){var n=t[o][1][e];return s(n?n:e)},f,f.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
var moment = require('moment');

module.exports = {
  now: function() { return moment().format(); },
  hello: function() { return 'Hello world'; }
};
},{"moment":"ZCrjYp"}],"Focm2+":[function(require,module,exports){
var _ = require('lodash');

var foo = require('./foo');

module.exports = function () {
  _.forEach(foo, function(fn, key) {
    console.log(key, fn());
  });
};
},{"./foo":1,"lodash":"G2vsx1"}],"robot":[function(require,module,exports){
module.exports=require('Focm2+');
},{}]},{},[])

  return require('robot');
}))

umd-head.js

(function(root, factory) {
  if(typeof exports === 'object') {
    module.exports = factory(require('lodash'), require('moment'));
  }
  else if(typeof define === 'function' && define.amd) {
    define(['lodash', 'moment'], factory);
  }
  else {
    root.robot = factory(root._, root.moment);
  }
}(this, function(_, moment) {
  var require = function(name) {
    return {'G2vsx1': _, 'ZCrjYp': moment}[name];
  };

umd-tail.js

  return require('robot');
}))