js_deep_freeze.js

function deepFreeze(obj){
    if (!Object.isFrozen(obj)){
        Object.freeze(obj);
    }

    for (var key in obj) {
        if ({}.hasOwnProperty.call(obj, key) || !(typeof obj[key] === 'function' || typeof obj[key] === 'object' && !!obj[key])) {
            continue;
        }

        deepFreeze(obj[key]);
    }
}