verdaccio/lib/logger.js

var Logger = require('bunyan')
  , Stream = require('stream')
  , utils = require('./utils')

function getlvl(x) {
	switch(true) {
		case x < 15: return 'trace'
		case x < 25: return 'debug'
		case x < 35: return 'info'
		case x == 35: return 'http'
		case x < 45: return 'warn'
		case x < 55: return 'error'
		default: return 'fatal'
	}
}

module.exports.setup = function(logs) {
	var streams = []
	if (logs == null) logs = [{ type: 'stdout', format: 'pretty', level: 'http' }]

	logs.forEach(function(target) {
		var stream = new Stream()
		stream.writable = true

		if (target.type === 'stdout' || target.type === 'stderr') {
			// destination stream
			var dest = target.type === 'stdout' ? process.stdout : process.stderr

			if (target.format === 'pretty') {
				// making fake stream for prettypritting
				stream.write = function(obj) {
					dest.write(print(obj.level, obj.msg, obj, dest.isTTY) + '\n')
				}
			} else {
				stream.write = function(obj) {
					dest.write(JSON.stringify(obj, Logger.safeCycles()) + '\n')
				}
			}
		} else if (target.type === 'file') {
			var dest = require('fs').createWriteStream(target.path, {flags: 'a', encoding: 'utf8'})
			dest.on('error', function (err) {
				Logger.emit('error', err)
			})
			stream.write = function(obj) {
				dest.write(JSON.stringify(obj, Logger.safeCycles()) + '\n')
			}
		} else {
			throw new Error('wrong target type for a log')
		}

		if (target.level === 'http') target.level = 35
		streams.push({
			type: 'raw',
			level: target.level || 35,
			stream: stream,
		})
	})

	var logger = new Logger({
		name: 'sinopia',
		streams: streams,
		serializers: {
			err: Logger.stdSerializers.err,
			req: Logger.stdSerializers.req,
			res: Logger.stdSerializers.res,
		},
	})

	module.exports.logger = logger
}

// adopted from socket.io
// this part was converted to coffee-script and back again over the years,
// so it might look weird

// level to color
var levels = {
	fatal: 31,
	error: 31,
	warn: 33,
	http: 35,
	info: 36,
	debug: 90,
	trace: 90,
}

var max = 0
for (var l in levels) {
	max = Math.max(max, l.length)
}

function pad(str) {
	if (str.length < max) return str + new Array(max - str.length + 1).join(' ')
	return str
}

var subsystems = [{
	in: '\033[32m<--\033[39m',
	out: '\033[33m-->\033[39m',
	fs: '\033[90m-=-\033[39m',
	default: '\033[34m---\033[39m',
}, {
	in: '<--',
	out: '-->',
	fs: '-=-',
	default: '---',
}]

function print(type, msg, obj, colors) {
	if (typeof type === 'number') type = getlvl(type)
	var finalmsg = msg.replace(/@{(!?[$A-Za-z_][$0-9A-Za-z\._]*)}/g, function(_, name) {
		var str = obj, is_error
		if (name[0] === '!') {
			name = name.substr(1)
			is_error = true
		}

		var _ref = name.split('.')
		for (var _i = 0; _i < _ref.length; _i++) {
			var id = _ref[_i]
			if (utils.is_object(str) || Array.isArray(str)) {
				str = str[id]
			} else {
				str = undefined
			}
		}

		if (typeof(str) === 'string') {
			if (!colors || ~str.indexOf('\n')) {
				return str
			} else if (is_error) {
				return '\033[31m' + str + '\033[39m'
			} else {
				return '\033[32m' + str + '\033[39m'
			}
		} else {
			return require('util').inspect(str, void 0, void 0, colors)
		}
	})
	var sub = subsystems[+!colors][obj.sub] || subsystems[+!colors].default
	//                   ^^--- black magic... kidding, just "colors ? 0 : 1"

	if (colors) {
		return ' \033[' + levels[type] + 'm' + (pad(type)) + '\033[39m ' + sub + ' ' + finalmsg
	} else {
		return ' ' + (pad(type)) + ' ' + sub + ' ' + finalmsg
	}
}