Install with npm or yarn

npm i @hoplin/nestjs-logger

yarn add @hoplin/nestjs-logger

NestJS custom logger

Extended NestJS Logger, Based on NestJS common logger. Log messages also follow Nest embedded style

• Support logfile
• Able to use logger with Dependency Injection
• Compatible with existing logging module
• Global request flow

Start logger

To use this logger, you need to import LoggerModule to app.module.ts via .forRoot() method.

import { LoggerModule } from '@hoplin/nestjs-logger';

@Module({
  imports: [
    LoggerModule.forRoot({
      applicationName: 'Logger Test',
      logfileDirectory: `${__dirname}/../`,
      saveAsFile: true,
      levelNTimestamp: {
        logLevels: ['log'],
        timestamp: true,
      },
    }),
  ],

...

forRoot() require some options. You can give two types of options, and each options refer to description under below

• applicationName - string
  • Name of application to be printed in the log message
• saveAsFile (optional) - boolean
  • true if you want to save log as logfile. If it's true, option logfileDirectory is not optional
• logfileDirectory (optional) - string
  • Directory where logfile will be saved.
• levelNTimestamp
  • logLevels(optional) - LogLevel[]
    • log level array. This work as same as NestJS Logger
  • timestamp(optional) - boolean
    • Check if logger print timestamp. timestamp mean, between current and previous log message.

For log level please refer json underbelow

{
  verbose: 0,
  debug: 1,
  log: 2,
  warn: 3,
  error: 4,
};

after initialize logger with .forRoot(), You can import LoggerModule from other Moduels throgh forFeature() and make DI to Injectable object

import { LoggerModule } from '@hoplin/nestjs-logger';

// example.module.ts
@Module({
  imports: [LoggerModule.forFeature()]

...
import { Logger } from '@hoplin/nestjs-logger';

// example.service.ts
@Injectable()
export class ExampleService {
  constructor(private readonly logger: Logger) {}

Global request / response flow interceptor

If you want to log to console about every request, use FlowInterceptor. You can both register globally or you can use it with @UseInterceptor() decorator, which NestJS provide

// main.ts
import { FlowInterceptor } from '@hoplin/nestjs-logger';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useGlobalInterceptors(new FlowInterceptor());
  ...

Example Log Message

• Enable Flow Interceptor globally