TypeScript decorator that changes method type signature

decoratorTest.ts

// tsconfig.json:
// {
//   "compilerOptions": {
//     "target": "es6",
//     "experimentalDecorators": true
//   }
// }

const decorator = (target: any, propertyKey: string, descriptor: PropertyDescriptor) => {
  const originalMethod = descriptor.value;
  descriptor.value = (a: number, b: number): number => originalMethod.call(this, a + b);
};


class A {
  @decorator
  method(n: number): number {
    return n;
  }
}

const a = new A();
a.method(1, 2);

Is it really working?

I dont think so