Accessing middleware injected data in Typescript-CodePudding

Here's a high level view of a controller in Typescript-Node :

As I'm storing details of user in product model, I have used a middleware to check if user if logged in before accessing the endpoint and also injecting user info to the req which can be further used in different controllers

exports.addProduct = async (req: Request, res: Response, next: NextFunction) => {
  // images:
  try {
    
    // logic to handle data from req.body

    // getting this user id from middleware isLoggedIn
    // injecting user id into request in the isLoggedIn middleware
    req.body.user = req.user._id;

    const product = await Product.create(req.body);
    return res.status(200).json({
      success: true,
      product,
    });
  } catch (error) {
    logger.error(error);
  }
};

Getting error : Property 'user' does not exist on type 'Request<ParamsDictionary, any, any, ParsedQs, Record<string, any>>' , on the line

req.body.user = req.user._id;

isLoggedIn is typical function to check Bearer token or header or cookies and then inject user info to the request

It worked Perfectly in Javascript, now trying same in Typescript as a part to learn Typescipt

CodePudding user response：

The problem is that according to the typing of req, there is no property named user. TypeScript is notifying you that req.user should be undefined, according to the available typings. There are some possible solutions to fix your problem.

You could explicitly type the variable as any. This is considered to be bad practice sometimes, because in general you should try to type everything correctly (nevertheless: it works).

// Option 1: Explicitly declare variable as any
req.body.user = (req as any).user._id;

You could also check if req.user is defined, like this:

// Option 2: Check req.user manually
if (req.user) req.body.user = req.user._id;
else throw new Error("Some Error");

You could also type the req correctly, according to the API specifications of your middleware. This is usually a lot of work if done manually. Some modules ship with correct TypeScript-typings already.

Maybe you want to also look into

now at yow endPoint you can apply it like this

import type e from "express";

export const endPoint: e.RequestHandler = (req, res, next) => {
//code
};

you can go beong that you can also add them params if there are any, the res body, the req body and stuff

const endPoint: e.RequestHandler<YowParamsObj,YowResBodyObj,YowReqBodyObj,ThemQueryParamsObj> = (req, res, next) => {
//code
};