Array-Unterklassenbildung mit Proxy-Interceptoren für geschützte Array-Mutationen

class GuardedArray extends Array {
  constructor(validator, ...items) {
    super(...items);
    return new Proxy(this, {
      set(target, prop, value, receiver) {
        if (typeof prop === 'string' && !isNaN(Number(prop))) {
          if (!validator(value)) {
            throw new TypeError(`Invalid value element '${value}' assigned at index ${prop}`);
          } 
        }
        return Reflect.set(target, prop, value, receiver);
      }
    });
  }
}
 
const numbersOnly = new GuardedArray((val) => typeof val === 'number', 10, 20);
numbersOnly.push(30);