bole-console/lib/index.js

Console formatter for the bole logger

'use strict';

var util = require('util');
var stream = require('stream');
var clone = require('clone');

var colors = {
  red: 31,
  green: 32,
  yellow: 33,
  blue: 34,
  magenta: 35,
  cyan: 36,
  gray: 90
};

var levelColors = {
  debug: colors.gray,
  info: colors.green,
  warn: colors.yellow,
  error: colors.red
};

var defaultProperties = {
  time: true,
  hostname: true,
  pid: true,
  level: true,
  name: true,
  message: true
};

var ConsoleStream = function (options) {
  stream.Writable.call(this, { objectMode: true });

  options = options || {};

  this._timestamp = options.timestamp;
  this._hostname = options.hostname;
  this._pid = options.pid;
  this._indent = options.indent || 2;
  this._colors = options.colors || true;
  this._requestDetails = options.requestDetails;
};

util.inherits(ConsoleStream, stream.Writable);

var localTime = function (date) {
  var tzo = -date.getTimezoneOffset();
  var diff = tzo >= 0 ? '+' : '-';
  var pad = function (n) {
    return (n < 10 ? '0' : '') + n;
  };
  var padMilliseconds = function (n) {
    var str = n + '';
    while (str.length !== 3) {
      str = '0' + str;
    }
    return str;
  };

  return date.getFullYear() + '-' +
      pad(date.getMonth() + 1) + '-' +
      pad(date.getDate()) + 'T' +
      pad(date.getHours()) + ':' +
      pad(date.getMinutes()) + ':' +
      pad(date.getSeconds()) + '.' +
      padMilliseconds(date.getMilliseconds()) +
      diff +
      pad(Math.abs(Math.floor(tzo / 60))) + ':' +
      pad(Math.abs(Math.floor(tzo % 60)));
};

ConsoleStream.prototype._write = function (obj, encoding, cb) {
  obj = clone(obj);
  var str = '';

  if (this._timestamp) str += localTime(new Date(obj.time)) + ' ';
  if (this._hostname) str += '[' + obj.hostname + '] ';
  if (this._pid) str += '[' + obj.pid + '] ';

  str += this._colorize(levelColors[obj.level], obj.level) +
      this._colorize(colors.magenta, ' [' + obj.name + ']') + ':';

  if (obj.message) str += ' ' + obj.message;
  if (obj.err) {
    var trace = obj.err.message || obj.err.name;
    trace = obj.err.stack.substring(obj.err.stack.indexOf(trace) +
        trace.length + 1);
    str += (obj.message ? ' - ' : ' ') +
        this._colorize(colors.cyan, obj.err.name + ': ' + obj.err.message);
    if (trace) str += '\n' + trace;
  } else if (obj.req) {
    str += (obj.message ? ' - ' : ' ') +
        this._colorize(colors.cyan, obj.req.method + ' ' + obj.req.url);
    obj.req.method = undefined;
    obj.req.url = undefined;
    if (this._requestDetails) {
      str += '\n' + JSON.stringify(obj.req, null, this._indent);
    }
  } else {
    var arbitraryObject = {};
    var content;

    for (var p in obj) {
      if (!obj.hasOwnProperty(p)) continue;
      if (!defaultProperties[p]) {
        content = true;
        arbitraryObject[p] = obj[p];
      }
    }

    if (content) {
      str += '\n' + JSON.stringify(arbitraryObject, null, this._indent);
    }
  }

  process.stdout.write(str + '\n');

  cb();
};

ConsoleStream.prototype._colorize = function (color, message) {
  return this._colors
      ? '\u001b[' + color + 'm' + message + '\u001b[0m'
      : message;
};

module.exports = function (options) {
  return new ConsoleStream(options);
};