快递中req和res的类型？

Question

In this demo I'm attempting to use the DefintelyTyped Response and Request types for the req, res parameters. However this does not compile:

const express = require('express');
const app = express();
app.get('/', (req:Request, res:Response) => {
    res.send('Hello Express Lovers!');
});
app.listen(3000, () => console.log('server started'));

The error is:

           ^
TSError: ⨯ Unable to compile TypeScript:
index.ts:4:9 - error TS2339: Property 'send' does not exist on type'Response'.

Answer 1

You should import Express the TypeScript way so its types (in @types/express ) come along, allowing the types of req and res to be inferred from app.get :

import * as express from 'express';
const app = express();
app.get('/', (req, res) => {
    res.send('Hello Express Lovers!');
});
app.listen(3000, () => console.log('server started'));

updated demo

If you wanted to type them explicitly anyway, you would have to import the types:

import * as express from 'express';
import {Request, Response} from 'express';
const app = express();
app.get('/', (req: Request, res: Response) => {
    res.send('Hello Express Lovers!');
});
app.listen(3000, () => console.log('server started'));