如何在 TypeScript 中使用扩展 `koa.Request` 的包？

Question

I am trying to use koa-tree-router and koa-bodyparser at the same time, but I keep getting TypeScript errors:

export const userLoggingRouter = new KoaTreeRouter<any, DefaultContext>();

userLoggingRouter.post('/logs/action', (ctx) => {
  const logEntries = ctx.request.body;
  const user = ctx.state.user;

  // ...
});

error TS2339: Property 'body' does not exist on type 'Request'.

I have @types/koa-bodyparser installed, and it contains the following definition:

import * as Koa from 'koa';

declare module 'koa' {
    interface Request {
        body: string | Record<string, unknown>;
        rawBody: string;
    }
}

But it doesn't seem to do anything. I found this question , but importing koa-bodyparser directly also does not do anything. How do I get TypeScript to recognize the extended Request type?

Edit: Creating a .d.ts file inside my project containing the following:

import {Request} from "koa";

declare module "koa" {
  interface Request {
    body: any;
  }
}

Made the compile error go away, but this seems like an inelegant solution because I would have to copy over type information for every package that modifies koa.Request .

Answer 1

This was happening because I was using Yarn PnP and I had two different versions of @types/koa installed. Once I added a resolutions field to my package.json that forced all of the other TypeScript definitions to use the same version of @types/koa , everything worked.