Logging by namespace

logging.js

/* Usage:
import { getLogger } from 'lib/utils/logging';
const log = getLogger('somename').log;
log('something');
*/

let loggers = {};

// retrieve a logger by name.
export const getLogger = function(namespace = '', color = DEFAULT_LOG_COLOR, enabled = true) {
    let l = loggers[namespace];
    if (!l) {
        l = new Logger(namespace, color, enabled);
    }
    loggers[namespace] = l;
    return l;
}

// debugs logs/arguments to a specific namespace (first parameter), or default.
export const log = function(...args) {
    const namespace = args.length > 1 ? args[0] : '';
    args = args.length > 1 ? args.slice(1, args.length) : [];

    let l = getLogger(namespace);
    if (l && l.enabled && process.env.IS_DEBUG == 'true') {
        let la = [...args];
        if (namespace) {
            la.unshift(`${colorMap[l.color]}${namespace}:${colorMap['reset']}`);
        }
        console.log.apply(console, la);
    }
}

export const colorMap = {
    'reset': '\x1b[0m',
    'black': '\x1b[30m',
    'red': '\x1b[31m',
    'green': '\x1b[32m',
    'yellow': '\x1b[33m',
    'blue': '\x1b[34m',
    'magenta': '\x1b[35m',
    'cyan': '\x1b[36m',
    'white': '\x1b[37m'
}
export const DEFAULT_LOG_COLOR = 'yellow';

export const IS_DEV = () => {
    return process.env.NODE_ENV != 'production';
}

export class Logger {
    namespace = '';
    color = 'yellow';
    enabled = true;

    public constructor(namespace, color = DEFAULT_LOG_COLOR, enabled = true) {
        this.namespace = namespace;
        this.color = color;
        this.enabled = enabled;
    }

    public log = (...args) => {
        if (this.enabled) {
            log(this.namespace, ...args);
        }
        return this;
    }

    public setEnabled(enabled) {
        this.enabled = enabled;
        return this;
    }
}