Sharing constants between node.js app and web app

app.js

//** In web app **//
var current = constants.STATE_WAITING;

contstants.js

'use strict';

/* jshint ignore:start */
(function(window){
    var constants = {
        STATE_COLD                    : 'STATE_COLD',
        STATE_WAITING                 : 'STATE_WAITING',
        STATE_GET_ALL                 : 'STATE_GET_ALL',
        STATE_MAINTENANCE             : 'STATE_MAINTENANCE',
    };
    if ( typeof module === 'object' && module && typeof module.exports === 'object' ) {
        module.exports = constants;
    } else {
        window.constants = constants;
    }
})( this );
/* jshint ignore:end */

server.js

//** In node.js app **//
var constants = require('../public/js/constants');
var all_states = [constants.STATE_COLD, constants.STATE_GET_ALL, constants.STATE_MAINTENANCE, constants.STATE_WAITING];