how to use inside a filter

[rubiin]

I want to use this inside a filter where i am catching all 500 exceptions. can anyone provide me with some snippet to get going

[gremo]

Hi, what do you mean "Use this inside a filter"?

[rubiin]

i want to use the logger as to log response inside a filter

[gremo]

There is no built-in method to log request and response, it's up to the developer. However, you can use any third party library like @algoan/nestjs-logging-interceptor (or try to just google for a more popular one).

Also take a look at #268 where I provide an example to log request and response using that libray.

EDIT: if you are talking about generic Nest filters, here is the way (copy/paste from Nest documentation, adding the logger with the dependency injection):

src/HttpExceptionFilter.ts

import {
  ExceptionFilter,
  Catch,
  ArgumentsHost,
  HttpException,
  Inject,
  LoggerService
} from '@nestjs/common';
import { Request, Response } from 'express';
import { WINSTON_MODULE_NEST_PROVIDER } from 'nest-winston';

@Catch(HttpException)
export class HttpExceptionFilter implements ExceptionFilter {
  constructor(@Inject(WINSTON_MODULE_NEST_PROVIDER) private readonly logger: LoggerService) { }

  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,
      });
  }
}

Use this way (src/app.controller.ts):

import { Controller, Get, UseFilters } from '@nestjs/common';
import { AppService } from './app.service';
import { HttpExceptionFilter } from './HttpExceptionFilter';

@Controller()
export class AppController {
  constructor(private readonly appService: AppService) {}

  @Get()
  @UseFilters(HttpExceptionFilter)
  getHello(): string {
    return this.appService.getHello();
  }
}

[rubiin]

@gremo can we make file transports optional. I only want them when NODE_ENV = production . for other environments, I only want console transaport

[gremo]

@rubiin have you see my example? Is this what you want? For making transport optional it fairly easy with a conditional.

[rubiin]

@rubiin have you see my example? Is this what you want? For making transport optional it fairly easy with a conditional.

yeah , I used the other i@algoan/nestjs-logging-interceptor works out of the box for my need

[gremo]

Good to know!

[rubiin]

can you provide me a snippet for making transport optional, i cannot seem to get it up

[gremo]

It could work this way (not tested) assuming app.modules.ts:

// Common Winston transports
let transports: winston.transport[] = [
  new winston.transports.Console({
    format: winston.format.combine(
      winston.format.timestamp(),
      nestWinstonModuleUtilities.format.nestLike(),
    ),
  }),
];

// Production Winston transports (common + custom)
if ('production' === process.env.NODE_ENV) {
  transports = [
    ...transports, new winston.transports.File({
      filename: 'logs/error.log',
      level: 'error',
    }),
  ]
}

@Module({
  imports: [
    WinstonModule.forRoot({
      transports: transports
    }),
  ],
})
export class AppModule {}

[rubiin]

cool