Logger module and service for Nest,
a progressive Node.js framework for building efficient and scalable server-side applications.

Installation

npm

npm install @andreafspeziale/nestjs-log

yarn

yarn add @andreafspeziale/nestjs-log

pnpm

pnpm add @andreafspeziale/nestjs-log

How to use?

Module

The module is Global by default.

LoggerModule.forRoot(options)

src/core/core.module.ts

import { Module } from '@nestjs/common';
import { LoggerModule } from '@andreafspeziale/nestjs-log';

@Module({
  imports: [
    LoggerModule.forRoot({
      level: LoggerLevel.Error,
      customLevelsOrder: false
      pretty: true,
      colorize: false,
      redact: ['password'],
      exclude: ['/swagger'] // Exclude routes from LoggerInterceptor
    }),
  ],
  ...
})
export class CoreModule {}

• level is optional and its default is Debug
• customLevelsOrder is optional and its default is false (Enables a personal levels hierarchy taste)
• pretty is optional and its default is true
• colorize is optional and its default is true
• redact is optional and its default is []
• exclude is optional and its default is []

BTW, using by using defaults you can ignore the provided schemas described in the "Environment variables management" chapter and just:

export const loggerModuleOptions = {
  level: LoggerLevel.Debug,
  customLevelsOrder: false,
  pretty: true,
  colorize: true,
  redact: [],
  exclude: [],
};

src/core/core.module.ts

import { Module } from '@nestjs/common';
import { LoggerModule } from '@andreafspeziale/nestjs-log';

@Module({
  imports: [
    LoggerModule.forRoot({}),
  ],
  ...
})
export class CoreModule {}

LoggerModule.forRootAsync(options)

src/core/core.module.ts

import { Module } from '@nestjs/common';
import { ConfigModule, ConfigService } from '@nestjs/config';
import { LoggerModule } from '@andreafspeziale/nestjs-log';
import { Config } from './config';

@Module({
  imports: [
    ConfigModule.forRoot({
      ....
    }),
    LoggerModule.forRootAsync({
      useFactory: (cs: ConfigService<Config, true>) => cs.get<ConfigService['logger']>('logger'),
      inject: [ConfigService],
    }),
  ],
  ....
})
export class CoreModule {}

Decorators

use the client and create your own service

InjectLoggerOptions() and InjectLogger()

src/samples/samples.service.ts

import { Injectable } from '@nestjs/common';
import {
  InjectLoggerOptions,
  InjectLogger,
  LoggerClient,
  LoggerModuleOptions,
  LoggerClient,
} from '@andreafspeziale/nestjs-log';

@Injectable()
export class SamplesService {
  constructor(
    @InjectLoggerOptions()
    private readonly loggerModuleOptions: LoggerModuleOptions, // Showcase purposes
    @InjectLogger() private readonly loggerClient: LoggerClient
  ) {}

  ....
}

Service

out of the box service with a set of features

LoggerService

src/samples/samples.service.ts

import { LoggerService } from '@andreafspeziale/nestjs-log';
import { SampleReturnType, MyParams } from './samples.interfaces'

@Injectable()
export class SamplesService {
  constructor(
    private readonly loggerService: LoggerService
  ) {
    this.logger.setContext(SamplesService.name);
  }

  async sampleMethod(params: MyParams): Promise<SampleReturn> {
    this.logger.debug('Doing something...', {
      fn: this.sampleMethod.name,
      params,
    });

    ....
  }
}

You'll see:

{
  context: 'SamplesService',
  fn: 'sampleMethod',
  params: {
    ....,
  },
  reqId: '557a8e30-62e6-11ef-b821-ebc5f38e9e30',
  level: 'debug',
  message: 'Doing something...',
  timestamp: '2024-08-25T13:31:28.843Z'
}

reqId will be there as soon as you developing a backend server and:

src/main.ts

import { rTracerFastifyMiddleware } from '@andreafspeziale/nestjs-log';

async function bootstrap() {
  const app = await NestFactory.create....;

  ....

  // I usually use Fastify but feel free to use Express importing rTracerExpressMiddleware instead of rTracerFastifyMiddleware
  app.use(rTracerFastifyMiddleware());

  ....

  await app.listen....;
}
bootstrap();

Middleware or Interceptor?

Use middleware in case of Express, use interceptor in case of Fastify.

At each request you'll see something like this:

{
  context: 'LoggerInterceptor',
  fn: 'intercept',
  request: {
    route: 'POST /whatever',
    query: {},
    body: {
      ....
    }
  },
  reqId: '557a8e30-62e6-11ef-b821-ebc5f38e9e30',
  level: 'http',
  message: 'Incoming request...',
  timestamp: '2024-08-25T13:31:28.798Z'
}

Middleware

src/core/core.module.ts

import { LoggerMiddleware, LoggerModule } from '@andreafspeziale/nestjs-log';
import { MiddlewareConsumer, Module, NestModule } from '@nestjs/common';

@Module({
  imports: [
    ....,
    LoggerModule....
  ],
  providers: [....],
})
export class CoreModule implements NestModule {
  configure(consumer: MiddlewareConsumer): void {
    consumer
      .apply(LoggerMiddleware)
      .exclude('(.*)/healthz', '/swagger(.*)', '/favicon.ico')
      .forRoutes('*');
  }
}

Interceptor

src/samples/samples.controller.ts

import { Body, Controller, Post, UseInterceptors } from '@nestjs/common';
import { LoggerInterceptor } from '@andreafspeziale/nestjs-log';
import { MyPayloadDTO, MyReturnDTO } from './dto';
import { SamplesService } from './samples.service';

@Controller('samples')
@UseInterceptors(LoggerInterceptor)
export class SearchController {
  constructor(private readonly samplesService: SamplesService) {}

  @Post()
  async search(@Body() payload: MyPayloadDTO): Promise<MyReturnDTO> {
    return this.samplesService.sampleMethod(payload);
  }
}

or

src/core/core.module.ts

import { LoggerInterceptor, LoggerModule } from '@andreafspeziale/nestjs-log';
import { Module } from '@nestjs/common';
import { APP_INTERCEPTOR } from '@nestjs/core';

@Module({
  imports: [
    ....,
    LoggerModule.... // Use the "exclude" module option to exclude routes from LoggerInterceptor
  ],
  providers: [{
    provide: APP_INTERCEPTOR,
    useClass: LoggerInterceptor,
  }],
})
export class CoreModule {}

Environment variables management

Please refer to @andreafspeziale/nestjs-search for more info about the environment variables features exported from my packages.

nestjs-log exports some features as well.

Zod

import { loggerSchema } from '@andreafspeziale/nestjs-log/dist/zod';

....

Class transformer/validator

import { LoggerSchema, ILoggerSchema } from '@andreafspeziale/nestjs-search/dist/class-validator';

....

Test

• pnpm test

Stay in touch

• Author - Andrea Francesco Speziale
• Website - https://nestjs.com
• Twitter - @nestframework

License

nestjs-log MIT licensed.