Leucine NPM | npm.io

✅ formatted, easy-to-read logs
✅ automatic distinction between server-side and client-side logging
✅ emoji first logging indicators
✅ comes with 4 logging states (debug, info, warn, error)
✅ easily configurable

Getting started

First, install leucine using npm/yarn/pnpn:

## npm
npm i leucine --save-dev

## yarn
yarn add leucine -D

## pnpm
pnpm add leucine -D

Then, import any of the logging modes as named imports:

import { debug, info, warn, error } from "leucine"

🎉 You're now ready to start logging:

const sum = (a, b) => a + b;

debug(sum(1,2)); //🐛 [01/01/2023 12:00:00] (debug) in index.ts: 3

Leucine formats logs in both the server side and client side environment, giving you a roundabout logging experience.

📘 Documentation

Configuring leucine

Leucine ships with a sensible, default configuration. Nonetheless, if you'd like to tinker with the defaults then you can do so in two ways: 1. Import the named configure function 2. Import the Leucine class and instantiate a new class with your configuration.

Both methods are viable, pick the one you're most comfortable with (using a function vs. using a class).

Then, pass in your configuration. Below we represent the available keys you can use to configure leucine:

import {configure} from "leucine" // function-based
import Leucine from "leucine" // class-based

configure({
    debugColor?: Colors;
	infoColor?: Colors;
	warnColor?: Colors;
	errorColor?: Colors;
	displayDate?: boolean;
	dateFormat?: DateFormat;
	displayTime?: boolean;
	showMilliseconds?: boolean;
	displayArgTypes?: boolean;  
})

const logger = new Leucine({
    debugColor?: Colors;
	infoColor?: Colors;
	warnColor?: Colors;
	errorColor?: Colors;
	displayDate?: boolean;
	dateFormat?: DateFormat;
	displayTime?: boolean;
	showMilliseconds?: boolean;
	displayArgTypes?: boolean;
})

To configure colors, import the Colors enum from leucine and use it when overriding the default colors:

import {Colors} from "leucine"

const configuration = {
    debugColor: Color.Red;
    //...
}

To configure date formatting, import the DateFormat enum from leucine and use it to override the default date formating:

import {DateFormat} from "leucine"
const configuration = {
    dateFormat: DateFormat.YEAR_MONTH_DAY   
    //...
}

Passing variable args to `log`

To pass a variable amount of arguments to log to the console or to log multiple things, use an array like so:

import {debug} from "leucine"

const someVar = "I'm a variable!"

debug(["This is a string", someVar, 10]) // 🐛 (debug): ["This is a string", "I'm a variable", 10]