tripitaka/lib/transports/emitter.js

A low dependency, no frills logger, designed to play nicely with tools like fluentd and Elasticsearch

const Level = require('../Level');

const DEFAULT_EVENTS = {
  [Level.TRACE.name]: 'log',
  [Level.DEBUG.name]: 'log',
  [Level.INFO.name]: 'log',
  [Level.WARN.name]: 'log',
  [Level.ERROR.name]: 'log',
};

module.exports = (params = {}) => {
  const { emitter = process, events = DEFAULT_EVENTS, level: threshold = Level.TRACE } = params;
  return ({ level, record }) => {
    if (!level.satisfies(threshold)) return;
    const event = events[level.name];
    emitter.emit(event, record);
  };
};