Node.js + Express + TypeScript：req.query 类型

在使用 Node 和 Express.js 时，可能存在需要访问req.query的情况，这是一个包含路由中每个查询字符串参数的属性的对象。例如，给定这样的路线：

http://localhost:3000?foo=abc&bar=def&something=123

然后req.query将如下所示：

{ foo: 'abc', bar: 'def', something: '123' }

如果您使用TypeScript编写代码，您可能想知道req.query 的 正确类型是什么？这个问题有不止一个解决方案。****

解决方案 1

Request接口（可以从express导入）是一个接受附加定义的泛型：

interface Request<
        P = core.ParamsDictionary,
        ResBody = any,
        ReqBody = any,
        ReqQuery = core.Query,
        Locals extends Record<string, any> = Record<string, any>
    > extends core.Request<P, ResBody, ReqBody, ReqQuery, Locals> {}

因此，我们可以这样做：

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

// interfaces
interface ReqParams {
  /* Add something as needed */
}
interface ReqBody {
  /* Add something as needed */
}
interface Resbody {
  /* Add something as needed */
}
interface ReqQuery {
  foo: string;
  bar: string;
  something?: string;
}

// controller
export const getThings = (
  req: Request<ReqParams, ReqBody, Resbody, ReqQuery>,
  res: Response,
  next: NextFunction
) => {
  const { foo, bar, something } = req.query;
  console.log(foo, bar, something);

  res.status(200).json({ message: 'Welcome to KindaCode.com!' });
};

解决方案 2

您还可以像这样使用类型转换：

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

// controller
export const getThings = (req: Request, res: Response, next: NextFunction) => {

  const foo: string = req.query.foo as string;
  const bar:string = req.query.bar as string;
  const something: string = req.query.something as string;
  console.log(foo, bar, something);

  res.status(200).json({ message: 'Welcome to KindaCode.com!' });
};