nanologger/index.js

var emojis = {
  debug: '🐛',
  info: '✨',
  warn: '⚠️',
  error: '🚨',
  fatal: '💀'
}

var levels = {
  debug: 20,
  info: 30,
  warn: 40,
  error: 50,
  fatal: 60
}

var colors = {
  foreground: '#d3c0c8',
  background: '#2d2d2d',
  black: '#2d2d2d',
  red: '#f2777a',
  green: '#99cc99',
  yellow: '#ffcc66',
  blue: '#6699cc',
  magenta: '#cc99cc',
  cyan: '#66cccc',
  white: '#d3d0c8',
  brightBlack: '#747369'
}

module.exports = Nanologger

function Nanologger (name) {
  if (!(this instanceof Nanologger)) return new Nanologger(name)

  this._name = name || ''

  try {
    this.logLevel = window.localStorage.getItem('logLevel') || 'info'
  } catch (e) {
    this.logLevel = 'info'
  }

  this._logLevel = levels[this.logLevel]
}

Nanologger.prototype.debug = function () {
  var args = [ 'debug' ]
  for (var i = 0, len = arguments.length; i < len; i++) args.push(arguments[i])
  this._print.apply(this, args)
}

Nanologger.prototype.info = function () {
  var args = [ 'info' ]
  for (var i = 0, len = arguments.length; i < len; i++) args.push(arguments[i])
  this._print.apply(this, args)
}

Nanologger.prototype.warn = function () {
  var args = [ 'warn' ]
  for (var i = 0, len = arguments.length; i < len; i++) args.push(arguments[i])
  this._print.apply(this, args)
}

Nanologger.prototype.error = function () {
  var args = [ 'error' ]
  for (var i = 0, len = arguments.length; i < len; i++) args.push(arguments[i])
  this._print.apply(this, args)
}

Nanologger.prototype.fatal = function () {
  var args = [ 'fatal' ]
  for (var i = 0, len = arguments.length; i < len; i++) args.push(arguments[i])
  this._print.apply(this, args)
}

Nanologger.prototype._print = function (level) {
  if (levels[level] < this._logLevel) return

  var time = getTimeStamp()
  var emoji = emojis[level]
  var name = this._name || 'unknown'

  var msgColor = (level === 'error' || level.fatal)
    ? colors.red
    : level === 'warn'
      ? colors.yellow
      : colors.green

  var objs = []
  var args = [ null ]
  var msg = '%c%s ' + emoji + ' %c%s'

  args.push(color(colors.brightBlack), time)
  args.push(color(colors.magenta), name)

  for (var i = 1, len = arguments.length; i < len; i++) {
    var arg = arguments[i]
    if (typeof arg === 'string') {
      if (i === 1) {
        // first string argument is in color
        msg += ' %c%s'
        args.push(color(msgColor))
        args.push(arg)
      } else if (/ms$/.test(arg)) {
        // arguments finishing with 'ms', grey out
        msg += ' %c%s'
        args.push(color(colors.brightBlack))
        args.push(arg)
      } else {
        // normal colors
        msg += ' %c%s'
        args.push(color(colors.white))
        args.push(arg)
      }
    } else if (typeof arg === 'number') {
      msg += ' %c%d'
      args.push(color(colors.magenta))
      args.push(arg)
    } else {
      objs.push(arg)
    }
  }

  args[0] = msg
  objs.forEach(function (obj) {
    args.push(obj)
  })

  console.log.apply(console, args)
}

function color (color) {
  return 'color: ' + color + ';'
}

function getTimeStamp () {
  var date = new Date()
  var hours = pad(date.getHours().toString())
  var minutes = pad(date.getMinutes().toString())
  var seconds = pad(date.getSeconds().toString())
  return hours + ':' + minutes + ':' + seconds
}

function pad (str) {
  return str.length !== 2 ? 0 + str : str
}