ThinkJS3.x log module, based on log4js.

npm install think-logger3

const Logger = require('think-logger3');
const logger = new Logger();
logger.debug('Hello World');

There has four log function you can use:

logger.info('info log');
logger.debug('debug log');
logger.warn('warn log');
logger.error('error log');

If you want to log file, you can use file adapter like this:

const Logger = require('think-logger3');
const logger = new Logger({
   handle: Logger.File,
   filename: __dirname + '/test.log'
});
logger.debug('Hello World');

This adapter will log to a file, and supports split log file by a constant file size. For example:

const Logger = require('think-logger3');
const logger = new Logger({
  handle: Logger.File,
  filename: __dirname + '/debug.log',
  maxLogSize: 50 * 1024,  //50M
  backups: 10 //max chunk number
})

Then initial log would create a file called debug.log. After this file reached maxLogSize, a new file named debug.log.1 will be created. After log file number reached backups, old log chunk file will be removed.

• filename: log filename
• maxLogSize: The maximum size (in bytes) for a log file, if not provided then logs won't be rotated.
• backups: The number of log files to keep after logSize has been reached (default 5)
• absolute: If filename is a absolute path, the absolute value should be true.
• layout: Layout defines the way how a log record is rendered. More layouts can see here.

This adapter will log to a file, moving old log messages to timestamped files according to a specified pattern. For example:

const Logger = require('think-logger3');
const logger = new Logger({
  handle: Logger.DateFile,
  filename: __dirname + '/debug.log',
  pattern: '-yyyy-MM-dd',
  alwaysIncludePattern: false
});

Then initial log would create a file called debug.log. At midnight, the current debug.log file would be rename to debug.log-2017-03-12(for example), and a new debug.log file created.

• level: log level
• filename: log base filename
• pattern: date filename would append to filename. A new file is started whenever the pattern for the current log entry differs from that of the previous log entry. The following strings are recognised in the pattern:
  • yyyy - the full year, use yy for just the last two digits
  • MM - the month
  • dd - the day of the month
  • hh - the hour of the day (24-hour clock)
  • mm - the minute of the hour
  • ss - seconds
  • SSS - milliseconds (although I'm not sure you'd want to roll your logs every millisecond)
  • O - timezone (capital letter o)
• alwaysIncludePattern: If alwaysIncludePattern is true, then the initial file will be filename.2017-03-12 and no renaming will occur at midnight, but a new file will be written to with the name filename.2017-03-13.
• absolute: If filename is a absolute path, the absolute value should be true.
• layout: Layout defines the way how a log record is rendered. More layouts can see here.

If those adapter configuration can't satisfy your need, you can use this adapter and set config like log4js. For example:

const Logger = require('think-logger3');
const logger = new Logger({
  handle: Logger.Basic,
  appenders: {
    everything: { type: 'file', filename: 'all-the-logs.log' },
    emergencies: {  type: 'file', filename: 'oh-no-not-again.log' },
    'just-errors': { type: 'logLevelFilter', appender: 'emergencies', level: 'error' }
  },
  categories: {
    default: { appenders: ['just-errors', 'everything'], level: 'debug' }
  }
});

All properties are as same as log4js except handle property. You can see more configure properties on log4js documentation.

Contributions welcome!

MIT