index.js

import debug from 'debug'

const colors = {
    red: {
        terminal: 1,
        rgb: '#ff0000',
    },
    green: {
        terminal: 2,
        rgb: '#00a000',
    },
    yellow: {
        terminal: 3,
        rgb: '#fcae05',
    },
    magenta: {
        terminal: 4,
        rgb: '#ad9aaf',
    },
    blue: {
        terminal: 5,
        rgb: '#004fd8',
    },
    gray: {
        terminal: 7,
        rgb: '#777777',
    },
}

const levels = {
    cfg: {
        color: colors.blue,
        suffix: 'CFG',
    },
    dbg: {
        color: colors.magenta,
        suffix: 'DBG',
    },
    log: {
        color: colors.gray,
        suffix: 'LOG',
    },
    info: {
        color: colors.green,
        suffix: 'INF',
    },
    warn: {
        color: colors.yellow,
        suffix: 'WRN',
    },
    error: {
        color: colors.red,
        suffix: 'ERR',
    },
}

const timeStrGet = date => {
    const msStr = date.getMilliseconds().toString().padStart(3, '0')
    const dateTimeStr = date.toLocaleTimeString('en-GB', {
        timeZone: 'UTC',
        year: '2-digit',
        month: '2-digit',
        day: '2-digit',
        hour12: false,
    })
    return `${dateTimeStr}.${msStr}`
}
const timestamp = function () {}
timestamp.toString = () => timeStrGet(new Date())

export const logger = {
    create(nameSpace) {
        const nsl = {
            handlers: {},
        }
        for (const [levelName, levelInfo] of Object.entries(levels)) {
            const {handlers} = nsl
            Object.defineProperty(nsl, levelName, {
                get() {
                    if (!nsl.handlers[levelName]) {
                        if (!nsl.instance) {
                            nsl.instance = debug(nameSpace)
                            // console.log(`lazyInit namespace ${nameSpace} useColors ${nsl.instance.useColors}`);
                        }
                        // console.log(`lazy init logger nameSpace ${nameSpace}:${levelInfo.suffix}`);
                        const handler = nsl.instance.extend(levelInfo.suffix)
                        // devtools timestamps can be enabled in settings
                        handler.log = window ? console.log.bind(console) : console.log.bind(console, '%s', timestamp)
                        const colorKey = window ? 'rgb' : 'terminal'
                        handler.color = levelInfo.color[colorKey]
                        handler.useColors = true
                        handlers[levelName] = handler
                    }
                    return handlers[levelName]
                },
            })
        }
        return nsl
    },
    init(namespacesList) {
        const namespaces = namespacesList.join(',')
        // console.log('logged namespaces:', namespaces);
        debug.enable(namespaces)
        // {
        //     const testLogger = logger.create('test-logger');
        //     ['cfg', 'dbg', 'log', 'info', 'warn', 'error',]
        //         .forEach(level => testLogger[level](`test level ${level} message`));
        // }
    },
}