source: frontend/node_modules/klona/lite/index.mjs

export function klona(x) {
        if (typeof x !== 'object') return x;

        var k, tmp, str=Object.prototype.toString.call(x);

        if (str === '[object Object]') {
                if (x.constructor !== Object && typeof x.constructor === 'function') {
                        tmp = new x.constructor();
                        for (k in x) {
                                if (x.hasOwnProperty(k) && tmp[k] !== x[k]) {
                                        tmp[k] = klona(x[k]);
                                }
                        }
                } else {
                        tmp = {}; // null
                        for (k in x) {
                                if (k === '__proto__') {
                                        Object.defineProperty(tmp, k, {
                                                value: klona(x[k]),
                                                configurable: true,
                                                enumerable: true,
                                                writable: true,
                                        });
                                } else {
                                        tmp[k] = klona(x[k]);
                                }
                        }
                }
                return tmp;
        }

        if (str === '[object Array]') {
                k = x.length;
                for (tmp=Array(k); k--;) {
                        tmp[k] = klona(x[k]);
                }
                return tmp;
        }

        if (str === '[object Date]') {
                return new Date(+x);
        }

        if (str === '[object RegExp]') {
                tmp = new RegExp(x.source, x.flags);
                tmp.lastIndex = x.lastIndex;
                return tmp;
        }

        return x;
}