@wing-logger/logger

Install

$ npm i @wing-logger/logger

Usage

import Logger, { ConsoleAppender } from '@wing-logger/logger';

const logger = new Logger('MY_CATEGORY');
logger.addAppender(new ConsoleAppender(logger));

logger.fatal('Fatal', { name: 'fatal' }); // √
logger.error('Error', { name: 'error' }); // √
logger.warn('Warn', { name: 'warn' }); // √
logger.info('Info', { name: 'info' }); // √
logger.debug('Debug', { name: 'debug' }); // √
logger.trace('Trace', { name: 'trace' }); // √

// all 6 of the above will be output to the console

Level

The log level of the logger instance. Default with Level.ALl both in instance and global.

Instance Level

import Logger, { ConsoleAppender, Level } from '@wing-logger/logger';

const logger = new Logger('MY_CATEGORY', Level.Info);
logger.addAppender(new ConsoleAppender(logger));

logger.fatal('Fatal', { name: 'fatal' }); // √
logger.error('Error', { name: 'error' }); // √
logger.warn('Warn', { name: 'warn' }); // √
logger.info('Info', { name: 'info' }); // √

// `debug` and `trace` will `not` be output to the console when level set as `Level.Info`
logger.debug('Debug', { name: 'debug' }); // ×
logger.trace('Trace', { name: 'trace' }); // ×

Global Level

The global level will affect all instances.

import Logger, { ConsoleAppender, Level } from '@wing-logger/logger';

const logger = new Logger('MY_CATEGORY', Level.All);
logger.addAppender(new ConsoleAppender(logger));

// set global level as `Level.Error`
Logger.globalLevel = Level.Error;
// only `fatal` and `error` will be output to the console when global level set as `Level.Error`
logger.fatal('Fatal', { name: 'fatal' }); // √
logger.error('Error', { name: 'error' }); // √

logger.warn('Warn', { name: 'warn' }); // ×
logger.info('Info', { name: 'info' }); // ×
logger.debug('Debug', { name: 'debug' }); // ×
logger.trace('Trace', { name: 'trace' }); // ×

Appender

$ npm i @wing-logger/appender

Tips

• Synchronization precedes asynchronization
• Synchronization is performed on a first-come-first-served basis.

ConsoleAppender

The default console appender

import Logger, { ConsoleAppender, Level } from '@wing-logger/logger';
const logger = new Logger('MY_CATEGORY');
logger.addAppender(new ConsoleAppender(logger));

logger.fatal('Fatal', { name: 'fatal' });
logger.error('Error', { name: 'error' });
logger.warn('Warn', { name: 'warn' });
logger.info('Info', { name: 'info' });
logger.debug('Debug', { name: 'debug' });
logger.trace('Trace', { name: 'trace' });

Sync Appender

• Generate a class that implements IAppender.

  import { type IAppender } from '@wing-logger/appender';
  import Logger, { Level } from '@wing-logger/logger';
  
  class SyncAppender1 implements IAppender {
    execute(level: Level, ...args: any[]) {
      console.log(`[Sync Appender_1] level=${level}`, ...args);
    }
  }
  
  class SyncAppender2 implements IAppender {
    execute(level: Level, ...args: any[]) {
      console.log(`[Sync Appender_2] level=${level}`, ...args);
    }
  }
  const logger = new Logger('MY_CATEGORY');
  
  logger.addAppender(new SyncAppender1());
  logger.addAppender(new SyncAppender2());
  
  logger.fatal('Fatal', { name: 'fatal' });
  logger.error('Error', { name: 'error' });
  logger.warn('Warn', { name: 'warn' });
  logger.info('Info', { name: 'info' });
  logger.debug('Debug', { name: 'debug' });
  logger.trace('Trace', { name: 'trace' });

Async Appender

• Generate a class that extends Appender.

  class AsyncAppender1 extends Appender {
    constructor() {
      super((level: Level, ...args: any[]): Promise<boolean> => {
        return new Promise((resolve) => {
          const label = `[Async Appender] level=${level} ${JSON.stringify(args)} took`;
          console.time(label);
          setTimeout(() => {
            console.timeEnd(label);
            resolve(true);
          }, 0);
        });
      });
    }
  }

  class AsyncAppender2 extends Appender {
    constructor() {
      super((level: Level, ...args: any[]): Promise<boolean> => {
        console.log(`[Async Appender_2] level=${level}`, ...args);
        return Promise.resolve(true);
      });
    }
  }

• Create an instance of Appender.

  function asyncExecuteHandler(level: Level, ...args: any[]): Promise<boolean> {
    console.log(`[Async ExecuteHandler] level=${level}`, ...args);
    return Promise.resolve(true);
  }

Async Appender Example:

import Appender from '@wing-logger/appender';
import Logger, { Level } from '@wing-logger/logger';
class AsyncAppender1 extends Appender {
  constructor() {
    super((level: Level, ...args: any[]): Promise<boolean> => {
      return new Promise((resolve) => {
        const label = `[Async Appender] level=${level} ${JSON.stringify(args)} took`;
        console.time(label);
        setTimeout(() => {
          console.timeEnd(label);
          resolve(true);
        }, 0);
      });
    });
  }
}
class AsyncAppender2 extends Appender {
  constructor() {
    super((level: Level, ...args: any[]): Promise<boolean> => {
      console.log(`[Async Appender_2] level=${level}`, ...args);
      return Promise.resolve(true);
    });
  }
}
function asyncExecuteHandler(level: Level, ...args: any[]): Promise<boolean> {
  console.log(`[Async ExecuteHandler] level=${level}`, ...args);
  return Promise.resolve(true);
}
const logger = new Logger('MY_CATEGORY');

logger.addAppender(new AsyncAppender1());
logger.addAppender(new AsyncAppender2());
logger.addAppender(new Appender(asyncExecuteHandler));

logger.fatal('Fatal', { name: 'fatal' });
logger.error('Error', { name: 'error' });
logger.warn('Warn', { name: 'warn' });
logger.info('Info', { name: 'info' });
logger.debug('Debug', { name: 'debug' });
logger.trace('Trace', { name: 'trace' });