Extending request and error handler

[fallen jewel]

I dont have any code but i tried that few days ago like what if i have extended the request interface of express for custom properties on request object and now i want to use those properties while i am handling error via a nest error handle which looks like this

import { ExceptionFilter, Catch, ArgumentsHost, HttpException } from '@nestjs/common';
import { Request, Response } from 'express';

@Catch(HttpException)
export class HttpExceptionFilter implements ExceptionFilter {
  catch(exception: HttpException, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    const request = ctx.getRequest<Request>();
    const status = exception.getStatus();

    response
      .status(status)
      .json({
        statusCode: status,
        timestamp: new Date().toISOString(),
        path: request.url,
      });
  }
}

The ctx response and request i am getting will not include my custom properties right bc it is referring to the express Request interface

[narrow pine]

So how are you wanting to extend the interfaces? Are you wanting to use declaration merging, or are you wanting to make a custom interface that extends them?

I personally find the custom interface more explicit, and therefore easier to work with, but then you have to remember it exists instead of just using the exisitng common interface

[fallen jewel]

I was using declaration merging for simplicity for testing like

Import {Request, Response} from "express"

Interface EnhancedRequest extends Request {
Context:string
}

I was unable to get the enhancedResponse via ctx.getrequest @narrow pine

[narrow pine]

context.swtchToHttp().getRequest<EnhancedRequest>()

[narrow pine]

Also, this isn;t declaration merging. This is just extending an interface. Declaration merging is something specific in Typescript

[fallen jewel]

But this is kind of easy for me to extend it tho it works with express also thanks for th reference im have a look at this concept never knew of it

[fallen jewel]

Uhh i think passing the enhanced request will throw error tho thanks for solution ima look more deeper into this and if i hit something this time i am providing full code with errors msges

[dull gust]

why wouldn't this less easy to extend?

declare global {
  namespace Express {
    interface Request {
      // props here
    }
  }
}

[narrow pine]

Why will using the EnhancedRequest interface cause an error?

[fallen jewel]

Sometime your code is so idiot that you also then need to specify the types files inside the tsconfig.json and also include exclude things so yeah

[fallen jewel]

Im not sure about this but i have seen something like that but I will pass on this for now

[narrow pine]

I use this custom interface approach without issue. Here's an example

[fallen jewel]

Mhm

Yeah you are using it inside the ctx mhm

Prolly _session is an array of obj

Damn thanks for the explanation

[dull gust]

I created a index.d.ts
And specified this file in the config

Also make sure the express types are installed