function updateDict(dict, update) {
    let key, value = update.entries()[0];
    dict[key] = value + (key in dict) ? dict[key] : 0;
}



aboba={"asd":123}
upd={"asd":123}
upd1={"asd":123}

updateDict(aboba,upd1)
console.log(aboba)
updateDict(aboba,upd1)
console.log(aboba)