tian-logger v1.0.0

tian-logger

A simple logger using async_hooks. With it you don't neet to pass logger everywhere.

Quick start

1. Install

npm i tian-logger

2. Usage

Create a logger with default writer in file ./globalLogger.js

const { Logger } = require('tian-logger');
const logger = new Logger({ level: 'info', meta: { meta1: '' } });
module.exports = logger;

Use the global logger anywhere

const globalLogger = require('./globalLogger');
globalLogger.info('message only');
// {"level":"info","time":"2020-08-03T11:49:30.110Z","message":"message only","meta":{"meta1":""},"data":{}}
globalLogger.error('error with data', new Error('error'));
// {"level":"error","time":"2020-08-03T12:34:11.846Z","message":"error with data","meta":{"meta1":""},"data":{"name":"Error","message":"error","stack":["file positions"]}}

Customize writer:

const { Logger } = require('tian-logger');
const fs = require('fs');
const logger = new Logger({
  writer: (object) => {
    // object is a object like
    // {
    //   message: "message",
    //   level: "debug|info|warn|error|fatal",
    //   time: "2020-08-03T10:42:25.415Z"
    //   meta: { meta1: '' },
    //   data: { field1: '' }
    // }
    fs.writeSync(1, JSON.stringify(object));
  }
})

API

Logger

constructor(options)

• options.level: 'debug' or 'info' or 'warn' or 'error' or 'final'. 'info' by default.
• options.meta: the object you want to add to current context.
• options.writer: customize writing logic

attach(meta)

Add meta data to current context.

• meta: the object you want to add to current context.

setLevel(level)

Change logging level.

• level: new logging level.

setWriter(writer)

Customize writer.

• writer: new writer.

debug(message, data)

Write message a debug level.

• message: logging message
• data: extra logging object

info(message, data)

Write message a info level.

• message: logging message
• data: extra logging object

warn(message, data)

Write message a warn level.

• message: logging message
• data: extra logging object

error(message, data)

Write message a error level.

• message: logging message
• data: extra logging object

final(message, data)

Write message a final level.

• message: logging message
• data: extra logging object