Does anyone know how to use interceptors with websockets?

[storm crane]

import {
    Injectable,
    NestInterceptor,
    ExecutionContext,
    CallHandler,
    Scope,
  } from '@nestjs/common';
  import { log, trace } from 'console';
  import { Request} from 'express';
  import { Observable } from 'rxjs';
  import { tap } from 'rxjs/operators';
  import { WinstonLoggerService } from 'src/common/loggers/winston-logger.service';
  
  @Injectable()
  export class LoggingInterceptor implements NestInterceptor {
    private readonly logger = new WinstonLoggerService(LoggingInterceptor.name)
    intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
      let req: Request = context.switchToHttp().getRequest()

      const message = {
        traceId: req.body.traceId,
        path: req.path,
        method: req.method,
        headers: req.headers,
        body: req.body,
        params: req.params,
        query: req.query
      }
  
      const data = {
        message: JSON.stringify(message)
      }
      
      return next.handle().pipe(tap(() => this.logger.log(data)))
    }
  }

But this code only handles http requests and responses. how do I handle websocket requests and responses?

[feral iris]

please don't use the suggestion to the fw tag unless you have some suggestion to the framework
Also, don't use the NestJS Devtools tag unless your question is related with https://devtools.nestjs.com (note the capital D)

[turbid river]

How is the interceptor being bound and used?

[storm crane]

Sorry did not know it

[storm crane]

ah so the thing is that when I put an interceptor in the module's class as a global interceptor it is not applied to websockets unless you use @useInterceptors() decrator manually for every websock function

[turbid river]

Yeah, global enhancers don't bind for websockets

[storm crane]

Yeah that is so sad

[turbid river]

I think we mention that somewhere, but I'd have to find it again

[storm crane]

we have hundreds of func in the code and we will have to put the decorator manually

for each of them

@turbid river do you know if there is websock middleware interface somehwere in nest.js? I could not find any

unfortunately

[turbid river]

You have hundreds of websocket gateway classes?

I'm not aware of Nest having a middleware interface for websockets.ws itself doesn't support it IIRC, so it's only an idea with socket.io. Technically you could make your own adapter that makes use of it, but nothing "official" to my knowledge

[storm crane]

functions

[storm crane]

Makes sense

[turbid river]

You can you the interceptor on the class and have it applied to all class methods

[storm crane]

that's right but I will have to write it for every class

I mean many classes yeah.

but okay makes sense

thanks though

btw another question

if you are still here

and if I dont bother you

so I have a exception filter class

and I want to put different exception classes there in the decorator

so in order to let my exeption filter catch all of those types of exception

do I need to override the catch function for every exception type

?

[turbid river]

How many exception types are you doing this for?

[storm crane]

two

WsException and HttpException

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

@Catch(HttpException, WsException)
@Injectable()
export class HttpExceptionFilter implements ExceptionFilter {
  catch(exception: HttpException, host: ArgumentsHost) 
  {        
  }
  catch(exception: WsException, host: ArgumentsHost) 
  {        
  }
}

can I do this for example?

[turbid river]

Yes
https://github.com/nestjs/nest/blob/master/packages/common/decorators/core/catch.decorator.ts#L21

[vestal pelican]

Well, you can't do this exactly, since Typescript still compiles to javascript and javascript doesn't do function overloading like you're used to from other compiled languages. What you can do is this:

@Catch(HttpException, WsException)
@Injectable()
export class HttpExceptionFilter implements ExceptionFilter {
  catch(exception: HttpException | WsException, host: ArgumentsHost) 
  {      
     if (exception instanceof HttpException) {
        return this.catchHttp(exception, host)
     } else {
        return this.catchWs(exception, host)
     }
  }
  catchHttp(exception: WsException, host: ArgumentsHost) 
  { }
  catchWs(exception: WsException, host: ArgumentsHost) 
  { }
}

[turbid river]

Oh crap, didn't even recognize the overload, just saw the catch decorator. Yeah, listen to papooch there

[storm crane]

Oh thank you so much I appreciate it ❤️

[storm crane]

** Argument of type 'HttpException' is not assignable to parameter of type 'WsException'.
Type 'HttpException' is missing the following properties from type 'WsException': error, getErrorts(2345) **

but it gives me this error

[vestal pelican]

I made a mistake in the code snippet, just change the exception type: catchHttp(exception: HttpException, host: ArgumentsHost)

[storm crane]

Oh my bad sorry

did not really take a look at it