Metaprogrammierung von Funktionsaufrufen mit Proxy-Apply-Traps

function createValidatedFunction(fn, validator) {
  return new Proxy(fn, {
    apply(target, thisArg, args) {
      if (!validator(...args)) {
        throw new TypeError('Invalid argument types provided to proxied function');
      }
      return Reflect.apply(target, thisArg, args);
    }
  });
}
 
const add = createValidatedFunction(
  (a, b) => a + b,
  (a, b) => typeof a === 'number' && typeof b === 'number'
);