koa 2.14.7 No generics，I want to be able to add generics

In koa 2.14.2, because there are no generics, the Context type needs to be overridden and inherited when using Koa-multer. Hopefully, the koa team will add generics in the next update

Code instance router：

import Router from "koa-router";
import article from "../../controller/article";
import authMiddleware from "../../middleware/authMiddleware";
import fileMiddleware from "../../middleware/fileMiddleware";

const articleRouter = new Router({
  prefix: "/article",
});

// 添加博客文章
articleRouter.post(
  "/",
  authMiddleware.verifyAuth,
  fileMiddleware.coverHandle,
  article.createArticle
);

export default articleRouter;

filemiddleware

import { Context, Next } from "koa";
import multer from "koa-multer";
import config from "../app/config";

// // 上传文件中间件

class FileMiddleware {
  async coverHandle(ctx:Context) {
    const coverUpload = multer({
      dest: config.COVER_PATH,
    });

    return coverUpload.single("cover");
  }
}

export default new FileMiddleware()

controller

import { Context } from "koa";
import { ArticleList, ArticleId, Article } from "../types/article";
import articleService from "../service/articleService";

import { IncomingMessage } from 'http'

interface ContextWithFile extends Context {
  req: IncomingMessage & { file?: unknown }
}

class articleController {
  // 添加博客文章
  async createArticle(ctx: ContextWithFile) {
    const { title, content, isShare } = ctx.request.body as Article;

    console.log(ctx.req.file);
  }
}

export default new articleController();

koajs / koa

koa 2.14.7 No generics，I want to be able to add generics #1764