Question

所以我看到了很多类似我遇到的问题，但是我不明白为什么会这样，所以请帮一个兄弟。

我有一个带有Express + Typescript的简单API，带有两个简单的控制器。家庭控制器，用于“默认”着陆路线“ localhost：port”。宠物小精灵控制器，用于在/ pokemon路线下获取宠物小精灵。

所有路由器都导出到index.ts文件中，并导入到server.ts中

home.controller.ts

import { Router, Request, Response } from "express";
const router: Router = Router();
router.get("/", (req: Request, res: Response) => {
    res.send("Hi, welcome to my Pokemon Api");
});
export const HomeController: Router = router;

pokemon.controller.ts

import { Router, Request, Response } from "express";
import Pokemon from "../entities/pokemon";
const router: Router = Router();
const pokemons: Pokemon[] = getPokemons(); // Get pokemons from a file/DB, irrelevant 

router.get("/", (req: Request, res: Response) => {
    if (pokemons !== undefined) {
        res.status(200).json(pokemons);
    } else {
        res.status(500).send("Error retrieving the list of Pokemons");
    }
});
export const PokemonController: Router = router;

index.ts

// note the order of these two controllers
export * from "./pokemon.controller";
export * from "./home.controller";

server.ts

import express from "express";
import { HomeController, PokemonController } from "./controllers";

const app: express.Application = express();
const port: number = 3000;

app.use("", HomeController);
app.use("/pokemon", PokemonController);

app.listen(port, () => {
    console.log(`Listening at port ${port}`);
});

好的，那么这段代码可以按预期100％运行。但是，如果在index.ts中切换控制器导出方式的顺序，则会崩溃。因此，如果我使用的不是上述内容， index.ts

export * from "./home.controller";
export * from "./pokemon.controller";

我收到此错误：TypeError：Router.use（）需要一个中间件功能，但未定义。

关于1.为什么会根据顺序发生该问题的任何想法（HomeController中一定有我没有得到的东西，以及2.如何在不切换index.ts导出顺序的情况下解决该问题？

StackTrace：

MYFOLDER\node_modules\express\lib\router\index.js:458
      throw new TypeError('Router.use() requires a middleware function but got a ' + gettype(fn))
            ^
TypeError: Router.use() requires a middleware function but got a undefined
    at Function.use (D:\Mese\Documentos\Proyectos\Pokeapp\PokeApp.api\node_modules\express\lib\router\index.js:458:13)
    at Function.<anonymous> (D:\Mese\Documentos\Proyectos\Pokeapp\PokeApp.api\node_modules\express\lib\application.js:220:21)
    at Array.forEach (<anonymous>)
    at Function.use (D:\Mese\Documentos\Proyectos\Pokeapp\PokeApp.api\node_modules\express\lib\application.js:217:7)
    at Object.<anonymous> (D:\Mese\Documentos\Proyectos\Pokeapp\PokeApp.api\app\server.ts:8:5)
    at Module._compile (module.js:653:30)
    at Module.m._compile (D:\Mese\Documentos\Proyectos\Pokeapp\PokeApp.api\node_modules\ts-node\src\index.ts:439:23)
    at Module._extensions..js (module.js:664:10)
    at Object.require.extensions.(anonymous function) [as .ts] (D:\Mese\Documentos\Proyectos\Pokeapp\PokeApp.api\node_modules\ts-node\src\index.ts:442:12)
    at Module.load (module.js:566:32)

Express TypeError：Router.use（）需要中间件功能，但未定义

0 个答案: