如何将Typescript定义添加到Express req&res

Question

我有一套用于REST API的控制器函数,我得到了很多以下内容

error TS7006: Parameter 'req' implicitly has an 'any' type.

同样地res.我一直在玩打字等但没有成功.例如,Request下面的类型参数不起作用.

以下是控制器文件的示例.参考路径是正确的.

/// <reference path="../../../typings/tsd.d.ts" />    
/* globals require */    
"use strict";    
exports.test = (req : Request, res) => {

我尝试添加import * as express from "express";到文件中 - 我不需要它正常,因为这些函数被导出并由index.js使用,它实际上实现了路由.

这是tsd.d.ts

/// <reference path="requirejs/require.d.ts" />
/// <reference path="express/express.d.ts" />
/// <reference path="mime/mime.d.ts" />
/// <reference path="node/node.d.ts" />
/// <reference path="serve-static/serve-static.d.ts" />
/// <reference path="bluebird/bluebird.d.ts" />
/// <reference path="mongoose/mongoose.d.ts" />

Answer 1

每次需要编写中间件函数时都键入参数可能会令人生畏，因此您也可以直接键入整个函数。

npm i @types/express --save-dev ("@types/express": "^4.17.0")

安装打字机后..

// This can be shortened..
import { Request, Response, NextFunction } from 'express';
export const myMiddleware = (req: Request, res: Response, next: NextFunction) => {
  ...
};

// to this..
import { RequestHandler } from 'express';
export const myMiddleware: RequestHandler = (req, res, next) => {
  ...
};

// or in case it handles the error object
import { ErrorRequestHandler } from 'express';
export const myMiddleware: ErrorRequestHandler = (err, req, res, next) => {
  ...
};

Answer 2

我发现您可以非常有效地利用 TypeScript 泛型来创建围绕 ExpressRequest类型的包装器。

您可以在接口文件/文件夹中声明与此类似的内容：

import { NextFunction, Request, Response } from 'express';

type TypedRequest<
  ReqBody = Record<string, unknown>,
  QueryString = Record<string, unknown>
> = Request<
  Record<string, unknown>,
  Record<string, unknown>,
  Partial<ReqBody>,
  Partial<QueryString>
>;

export type ExpressMiddleware<
  ReqBody = Record<string, unknown>,
  Res = Record<string, unknown>,
  QueryString = Record<string, unknown>
> = (
  req: TypedRequest<ReqBody, QueryString>,
  res: Response<Res>,
  next: NextFunction
) => Promise<void> | void;

TypedRequest实际上是 Express 接口的包装器Request，并用您传递给它的泛型填充它，但也是可选的（注意。然后它还会在每个泛型周围Record<string, unknown>应用 a （您可能希望将其改为 a ）PartialDeepPartial

ExpressMiddleware接受 3 个可选泛型ReqBody Res和QueryString. 它们用于构造类似于中间件/控制器的函数签名。

然后，上面的内容允许您强类型和消费，如下所示：

import { ExpressMiddleware } from '../interfaces/ExpressMiddleware';

type Req = { email: string; password: string };

type Res = { message: string };

export const signupUser: ExpressMiddleware<Req, Res> = async (req, res) => {
  /* strongly typed `req.body`. yay autocomplete  */
  res.json({ message: 'you have signed up' }) // strongly typed response obj
};

我希望这可以帮助别人。这对我的 Express 体验产生了巨大的影响。

Answer 3

您可以使用名为import的ES6样式仅导入所需的接口,而不是import * as express from 'express'包含express本身.

首先确保已安装express(npm install -D @types/express)的类型定义.

例:

// middleware/authCheck.ts
import { Request, Response, NextFunction } from 'express';

export const authCheckMiddleware = (req: Request, res: Response, next: NextFunction) => {
  ...
};

// server.ts
import { authCheckMiddleware } from './middleware/authCheck';
app.use('/api', authCheckMiddleware);

目前使用TypeScript 2.3.4和@ types/express 4.0.36.

我有同样的问题,所以我想我会提供一个答案,万一其他人遇到这个问题.