Package Exports

@midwayjs/logger
@midwayjs/logger/dist/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@midwayjs/logger) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

@midwayjs/logger

@midwayjs/logger is a log module for midway project.

Required

Node.js >= v20 since v4.0.0

Install

$ npm install @midwayjs/logger --save

Create Logger

import { loggers } from '@midwayjs/logger';

const logger = loggers.createLogger('logger', {
  // some logger options
})

Create With Transport

Create logger with console and file transports instance.

import { loggers, ConsoleTransport, FileTransport } from '@midwayjs/logger';

const logger = loggers.createLogger('logger', {
  transports: {
    console: new ConsoleTransport(),
    file: new FileTransport({
      dir: '...',
      fileLogName: 'app.log',
    }),
  }
})

Create console logger.

const logger = loggers.createLogger('consoleLogger', {
  transports: {
    console: new ConsoleTransport(),
  }
})

Create logger with options mode.

const logger = loggers.createLogger('consoleLogger', {
  transports: {
    console: {
      autoColors: true,
    },
    file: {
      dir: '...',
      fileLogName: 'app.log',
    }
  }
})

Logger Output Method

logger.debug('debug info');
logger.info('启动耗时 %d ms', Date.now() - start);
logger.warn('warning!');
logger.error(new Error('my error'));
logger.write('abcde');

Logger Level

log level is divided into the following categories, and the log level decreases sequentially (the larger the number, the lower the level):

const levels = {
  none: 0,
  error: 1,
  trace: 2,
  warn: 3,
  info: 4,
  verbose: 5,
  debug: 6,
  silly: 7,
  all: 8,
}

Set level for all transports

const logger = loggers.createLogger('logger', {
  // ...
  level: 'warn',
});

// not output
logger.debug('debug info');

// not output
logger.info('debug info');

Format and ContextFormat

Add logger format and context format.

const logger = loggers.createLogger('logger', {
  // ...
  format: info => {
    return `${info.timestamp} ${info.message}`;
  },
  contextFormat: info => {
    return `${info.timestamp} [${info.ctx.traceId}] ${info.message}`;
  }
});

info is a default metadata, include some properties.

Tranports

The actual behavior of the log output we call the transport.The log library has four built-in default Transports.

ConsoleTransport Output message to stdout and stderr with color.
FileTransport Output message to file and rotate by self.
ErrorTransport Inherit FileTransport and only output error message.
JSONTransport Inherit FileTransport and output json format.

The above Transports are all registered by default and can be configured by the name when registering.

const logger = loggers.createLogger('consoleLogger', {
  transports: {
    console: {/*...options*/},
    file: {/*...options*/},
    error: {/*...options*/},
    json: {/*...options*/},
  }
});

Implement a new Transport

Inherit Transport abstract class and implement log and close method.

import { Transport, ITransport } from '@midwayjs/logger';

export interface CustomTransportOptions {
  // ...
}

export class CustomTransport extends Transport<CustomTransportOptions> implements ITransport {
  log(level: LoggerLevel | false, meta: LogMeta, ...args) {
    // save file or post to remote server
  }
  
  close() {}
}

import { TransportManager } from '@midwayjs/logger';

TransportManager.set('custom', CustomTransport);

And you can configure it in your code.

const logger = loggers.createLogger('consoleLogger', {
  transports: {
    custom: {/*...options*/}
  }
});

Default Logger Options

find more options in interface.

License

MIT