decorator_example.ts

interface Constructor<T> {
  new(...args: []): T;
}

interface Base {
}

interface Items {
  items: [];
}

function SubClass<T extends Base>(SuperClass: Constructor<T>) {

  let temp = SuperClass.prototype.log;
  if (temp) {
    SuperClass.prototype.log = function (...args: any) {
      this.items.push(args[0]);
      temp.apply(this, args);
    }
  }

  class C extends (<Constructor<Base>>SuperClass) {
    items = [];
  }

  return <Constructor<Items & T>>C;
}

@SubClass
class Person {
  log(msg: string) {
    console.log(msg);
  }
}

// let P = SubClass(Person);
// let p = new P();
// p.log('hello');
// p.log('bye');
// console.log(p.items);

let p = new Person();
p.log('hello');
p.log('bye');
console.log(p['items']);