snippets.js

const has = (obj, key) => Object.hasOwnProperty.call(obj, key);

let deepCopy = (obj, res) => {
    let keys = Object.keys(obj);
    let result = res || {};

    keys.forEach(key => {
        if ('object' != typeof obj[key] && has(obj, key)) {
            result[key] = obj[key];
        } else {
            result[key] = deepCopy(obj[key]);
        }
    });
    return result;
};