// Like array.map, but for objects
const mapObj = <U, T extends object>(
  obj: T,
  mapFn: (val: T[keyof T], key?: keyof T) => U
): { [K in keyof T]: U } => {
  return Object.assign(
    {},
    ...Object.entries(obj).map(([k, v]) => ({ [k]: mapFn(v, k as keyof T) }))
  );
};