A tiny little logger written in JS

logger.alt.js

const LEVELS = [ 'debug', 'info', 'warn', 'error' ];
const DEFAULT_LEVEL = 'info';

function Logger(logLevel = DEFAULT_LEVEL) {
	if (!LEVELS.includes(logLevel)) throw new Error('Invalid log level');

	LEVELS.forEach(level => {
		const consoleLog = level in console ? console[level] : console.log;

		Logger.prototype[level] = (...msg) =>
			LEVELS.indexOf(level) >= LEVELS.indexOf(logLevel) &&
			consoleLog(`[${new Date().toLocaleString()}]`, `${level.toUpperCase()}:`, ...msg);
	});
}

module.exports = Logger;

logger.js

const LEVELS = [ 'debug', 'info', 'warn', 'error' ];
const DEFAULT_LEVEL = 'info';

module.exports = {
	register: (logLevel = DEFAULT_LEVEL) => {
		if (!LEVELS.includes(logLevel)) throw new Error('Invalid log level');

		const globals = typeof global !== 'undefined' ? global : window;

		LEVELS.forEach(level => {
			const consoleLog = level in console ? console[level] : console.log;

			globals[level] = (...msg) =>
				LEVELS.indexOf(level) >= LEVELS.indexOf(logLevel) &&
				consoleLog(`[${new Date().toLocaleString()}]`, `${level.toUpperCase()}:`, ...msg)
		})
	},
};

USAGE.md

USAGE

// Get log level (f.e. "info")
require('dotenv').config();
const { LOG_LEVEL } = process.env;


// Register logger
require('./logger').register(LOG_LEVEL);


// Use logger
debug('This is a debug message');
info('This is an info message');
warn('This is a warning message');
error('This is an error message');

ALT USAGE

// Get log level (f.e. "info")
require('dotenv').config();
const { LOG_LEVEL } = process.env;


// Init logger
const Logger = require('./logger');
const log = new Logger(LOG_LEVEL);


// Use logger
log.debug('This is a debug message');
log.info('This is an info message');
log.warn('This is a warning message');
log.error('This is an error message');