node-slogger

A wrapper of logger package , let you wirte log easy.

Install

npm install node-slogger

How to use

The fist demo

The slogger t will print log to console with prefix of time string and log level, for example slogger.debug('debug') will print Thu Dec 15 2016 11:04:50 GMT+0800 (CST) [DEBUG] debug . Different function will be printed with different color.

const {Slogger} = require('node-slogger');
var slogger = new Slogger();

slogger.debug('debug');
slogger.info('info');
slogger.trace('trace');
slogger.warn('warn');
slogger.error('error');

Saving log to file

const path = require('path');
const fs = require('fs')
const {Slogger, LogLevel} = require('node-slogger');

const slogger = new Slogger({
    streams:{
	    [LogLevel.ERROR]: fs.createWriteStream(path.join(__dirname , './log/error.log'))
    }
});

slogger.debug('debug');//only print to console
slogger.info('info');//only print to console
slogger.trace('trace');//only print to console
slogger.warn('warn');//only print to console
slogger.error('error');//print to console and write to the file

The code of file_test.js

Printing the log to console delayed with fixed interval.

If you wanna you project run with high performance, printing to console frequently will cost a lot of cpu time. So slogger provide a feature of printing log in delay time with a fixed interval.

const {Slogger} = require('node-slogger');
const slogger = new Slogger({flushInterval:500});
slogger.debug('this is a delay log');//it will show after 500ms

Setting the log level

You can set the level of log , just use the option of level. For example we set it to warn:

const {Slogger} = require('node-slogger');
const slogger = new Slogger({level:'warn');

slogger.debug('debug');
slogger.info('info');
slogger.trace('trace');
slogger.warn('warn');
slogger.error('error');

The code of level_test.js
Only the warn adn error log will be printed as we set the level option to warn.

API

See the document of api.

Known issues

1. Not showing log on VS Code's debug panel

You should modify the launch.json and add the parameter outputCapture with the value std and parameter console with internalConsole. This is an example:

{
    "type": "node",
    "request": "launch",
    "name": "Mocha Tests",
    "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha",
    "args": [
        "-u",
        "tdd",
        "--timeout",
        "999999",
        "--colors",
        "${workspaceFolder}/src/test/mocha"
    ],
    "console": "internalConsole",
    "outputCapture": "std",
    "internalConsoleOptions": "openOnSessionStart"
},

Breaking changes on 3.x

1. Singleton object are no longer the default exported and must be manually created based on the exported slogger class.

// code in 2.x and below
const slogger = require('node-slogger').init({});

// code in 3.x
const { Slogger } = require('node-slogger');
const slogger = new Slogger();

2. Support for input file objects has been removed. Now, it is required to use a writeable stream instead.

// code in 2.x and below
const path = require('path');
const slogger = require('node-slogger').init({
    logFiles:[
        {category:'error',filename:path.join(__dirname , './log/error.log')}
    ]
});

// code in 3.x
const { Slogger } = require('node-slogger');
const fs = require('fs');
const slogger = new Slogger({
    streams:{
      [LogLevel.ERROR]: fs.createWriteStream(path.join(__dirname , './log/error.log'))
    }
});

3. Useless Kafka feature support has been removed.
4. Drop the support for node 12 and below.

License

MIT