Javascript Logger

log.json

{
        "colorsEnabled": true,
        "defaultConf": {
                "info": {
                        "enabled": false,
                        "color": "Blue"
                },
                "warning": {
                        "enabled": true,
                        "color": "Yellow"
                },
                "error": {
                        "enabled": true,
                        "color": "Red"
                }
        },
        "packagepath": "../package.json"
}

logger.js

// Define color codes for terminal emulators
const Colors = {
        Reset: "\x1b[0m",
        Bright: "\x1b[1m",
        Dim: "\x1b[2m",
        Underscore: "\x1b[4m",
        Blink: "\x1b[5m",
        Reverse: "\x1b[7m",
        Hidden: "\x1b[8m",

        FgBlack: "\x1b[30m",
        FgRed: "\x1b[31m",
        FgGreen: "\x1b[32m",
        FgYellow: "\x1b[33m",
        FgBlue: "\x1b[34m",
        FgMagenta: "\x1b[35m",
        FgCyan: "\x1b[36m",
        FgWhite: "\x1b[37m",

        BgBlack: "\x1b[40m",
        BgRed: "\x1b[41m",
        BgGreen: "\x1b[42m",
        BgYellow: "\x1b[43m",
        BgBlue: "\x1b[44m",
        BgMagenta: "\x1b[45m",
        BgCyan: "\x1b[46m",
        BgWhite: "\x1b[47m"
}

function generateConfig(loggerConfig) {
        let {packagepath, defaultConf} = loggerConfig;
        let {name, version} = require(packagepath);

        return {
                logLevels: require('process').argv.slice(2).reduce(
                        (config, arg) => {
                                if (arg.startsWith('-l')) {
                                        config[arg.slice(2)].enabled = true;
                                }
                                else if (arg.startsWith('-lr')) {
                                        config[arg.slice(3)].enabled = false;
                                }
                                return config;
                        },
                        defaultConf
                ),
                name: name,
                version: version,
        }
}

module.exports = class Logger {
        constructor(config) {
                // Don't print color codes when colors are not enabled
                this.colors = new Proxy(Colors, {
                        get: function(obj, prop) {
                                return config.colorsEnabled ? obj[prop] : "";
                        }
                })
                this.config = generateConfig(config);
                this.generateLogFunctions();
                this.printHead();
        }

        generateLogFunctions() {
                Object.keys(this.config.logLevels).forEach( name => this[name] = this.logFunction(name));
        }

        logFunction(name, enabled) {
                return message => this.config.logLevels[name].enabled &&
                        console.log(`[${this.colors['Fg' + this.config.logLevels[name].color] + name + this.colors.Reset}] message`);
        }

        printHead() {
                // Prints head text like so:
                // npm-package-name v7.6.0
                console.log(`${this.colors.BgBlue + this.colors.FgWhite + this.config.name + this.colors.Reset} v${this.config.version}`)
        }

}

let l = new Logger(require("./log.json"));
l.info('test')
l.warning('test2')
l.error('test3')