TypeScript:从装饰器推断返回类型?

如何让TypeScript在修饰器更改其返回类型时推断修饰方法的类型?

在下面的基本示例中,我修饰了一个方法以返回字符串化对象:

function jsonStringify() {
  return function (target, decoratedFnName: string, descriptor: PropertyDescriptor) {
    let decoratedFn = descriptor.value;

    let newFn = function () {
      let object = decoratedFn.apply(target, arguments);

      return JSON.stringify(object);
    };

    descriptor.value = newFn;

    return descriptor;
  }
}

class Decorated {
  @jsonStringify()
  method(name: string, description: string) {
    return {
      name: name,
      description: description
    }
  }
};

let stringifiedObject = new Decorated().method('Test Name', 'Test Description');

console.log(stringifiedObject.includes('Test Name'));

如果我用 "noEmitOnError": false 在tsconfig中。json,则代码可以完美运行,并在控制台中记录true。然而,tsc投诉错误:

error TS2339: Property 'includes' does not exist on type '{ name: string; description: string; }'.

我理解是因为 Decorated.method() 返回一个对象而不是字符串,但此方法有一个返回字符串的装饰器。我需要做什么才能让TypeScript从装饰器推断出类型?