Better Logger

Easy and lightweight console logging for your JavaScript and TypeScript projects. Control log levels in development vs production, integrate with third-party log tools and debug Vue applications.

Features

• Log levels that follow and extend browser console log levels
• success, critical and run methods for more secure and informative logging
• Nice looking and fully configurable output
• Custom formatter for Vue
• Full TypeScript support
• Good test coverage

Installation

pnpm add @slipmatio/logger

Basic Usage

The easiest way to use this logger is to use the useLogger or useVueLogger helpers. The helpers are configured to print only errors in production and print all but debug messages in development mode unless called with debug=true. You can also set the logger name attribute. Both arguments are optional:

import { useLogger } from '@slipmatio/logger'

const logger = useLogger()

Then just use logger wherever you want:

logger.log('Hello World!')
// > Hello world!

logger.run()
// > 🚀 [main.ts]

Vue Logger

Vue logger uses a special logger function that pretty prints ref, reactive, and computed objects for you so instead of unreadable garble you can read the logs easily.

import { ref, computed } from 'vue'
import { useVueLogger } from '@slipmatio/logger'

const logger = useVueLogger('vuelogger')

const num = ref(1)
const timesTwo = computed(() => num.value * 2)

console.log('proxy objects', num, timesTwo)
// > proxy objects  Object { __v_isShallow: false, dep: undefined, __v_isRef: true, _rawValue: 1, _value: 1 } Object { _setter: setter(), dep: undefined, __v_isRef: true, __v_isReadonly: true, _dirty: true, effect: {…}, _cacheable: true }
logger.log('proxy objects', num, timesTwo)
// > [vuelogger] proxy objects (ref): 1 (computed): 2

Automatic Imports

Tip: use something like unplugin-auto-import with your bundler to automagically import your logger instance wherever you need it.

Setting Up Manually

You can also instantiate and import the logger manually. It works as you'd expect:

import { Logger, LogLevel } from '@slipmatio/logger'

const logger = new Logger({
  // Log levels: DEBUG, INFO, WARN, ERROR, CRITICAL, OFF
  logLevel: process.env.NODE_ENV !== 'production' ? LogLevel.INFO : LogLevel.ERROR,
  name: 'mylogger',
  logFn: myLogFn, // see source for implementation
})

Status

This project was originally born around 2016 and has been copy-pasted in various formats from project to project. As it has been helpful in so many projects, I finally decided to clean it up, convert to TypeScript and release as open source. Some parts of the code are a bit ugly, but it works well enough for most production needs. Contributions welcome!

Elsewhere

Follow @uninen on Twitter