如何使用typescript中的装饰器修改描述符

Question

所以我有这个方法，我想变成一个装饰器：

function MethodRead< Data, Output extends Mongo.Cursor<Data> >( 
    method: (...args: any[]) => Output, 
    opt: IOptions = {} 
) {
    return (...args: any[]) => {
        const sub = doSomeProcessing(method(...args), opt);
        return {
            ready: () => sub.ready(),
            fetch: () => sub.fetch(),
        };
    };
}

此方法的输入（参数除外）都匹配并且运行良好。

然而，当我试图将它变成装饰器时，似乎打字稿只是没有干净的方式处理这个逻辑...

function DecoratorRead<Data>(opt: IOptions) {
    return <C, K extends keyof C> ( 
        target: C, 
        propName: K, 
        descriptor: TypedPropertyDescriptor<C[K]> 
    ): TypedPropertyDescriptor<Reader<Data>> => {
        descriptor.value = (...args: any[]) => {
            const sub = doSomeProcessing(method(...args), opt);
            return {
                ready: () => sub.ready(),
                fetch: () => sub.fetch(),
            };
        }
        return descriptor;
    }
}

所以，我用打字稿得到的错误是这样的：

Type 'TypedPropertyDescriptor<C[K]>' is not assignable to type 'TypedPropertyDescriptor<Reader<Data>>'.
  Type 'C[K]' is not assignable to type 'Reader<Data>'.

Type '(...args: any[]) => { ready: () => boolean; fetch: () => Data; }' is not assignable to type 'Method<Data>'.
  Type '{ ready: () => boolean; fetch: () => Data; }' is not assignable to type 'Data'.

以下是一些其他类型的帮助：

interface IOptions {
     auth: boolean;
}
type Method<Data> = (...args: any[]) => Data;
type Reader<Data> = (...args: any[]) => {
    ready: () => boolean;
    fetch: () => Data;
}

function doSomeProcessing<Data>( data: Data , opt: IOptions ) : {
    ready: () => boolean;
    fetch: () => Data;
};