JS data types

controller.js

$http.get('hostname/remote/service').success(function (data) {

     // this way we document remote data type
     var resultInterval = new DateInterval(data);

});

Hotel.js

(function () {
    'use strict';

    module.exports = function () {
        var state = arguments[0] || {};

        return Object.seal({
            id: state.id,
            name: state.name
        });
    };

})();

somewhere.js

var Hotel = require ('./Hotel.js'),
    hotelArosa = new Hotel({
        id: '123456',
        name: 'Hotel Arosa'
    }),
    newHotel = new Hotel();

types.js

(function () {
    'use strict';

    function DateInterval() {
        var state = arguments[0] || {};

        Object.defineProperties(state, {
            "from": {
                value: state.from,
                writable: true,
                enumerable: true
            },
            "to": {
                value: state.to,
                writable: true,
                enumerable: true
            }
        });

        return Object.seal(state);
    }

    var i1 = new DateInterval(),
        i2 = new DateInterval({from: '2014-01-02', to: '2014-01-03'});

    // mutable
    i1.from = (new Date()).toJSON();
    i1.to = (new Date()).toJSON();

    console.log(i1);
    console.log(i2);

    // serializable
    console.log(JSON.stringify(i1));

    // protected from accidental mistakes
    console.log(i1.undefined);
    i1.newProperty = {};

})();