Custom console logging system

console.js

/**
 * Custom Logging Module to support older browsers & timestamp in console log.
 * 
 * Caveats:
 * 
 * - Errors are not logged on the correct line.
 * 
 * @param {String} environment
 * @return {Object}
 */
var log = function (environment) {
  var environments = {
    TESTING: 'TESTING',
    PRODUCTION: 'PRODUCTION'
  };
  
  /*!
   * Delegate 
   * 
   * @private
   */
  var prepare = function (args, timestamp) {
    var a = Array.prototype.slice.call(args, 0);
    if (timestamp) a.unshift(self.timestamp());
    return a;
  };

  /**
   * Sugar to alias console methods to our log module.
   * 
   * @param  {String} method
   * @return {Function}
   * @private
   */
  var type = function (method, timestamp) {
    var terminal = window.console;

    return function () {
      if (terminal && terminal[method]) terminal[method].apply(terminal, prepare(arguments, timestamp));
    }
  };

  /**
   * Module
   * 
   * @type {Function}
   */
  var self = function () {
    var alias = type('log', true);

    return (environment == environments.TESTING) ? alias.apply(this, Array.prototype.slice.call(arguments)) : undefined;
  };
  
  /**
   * Environment
   * 
   * @type {String}
   */
  self.environment = environment || environments.TESTING;

  /*!
   * Generate timestamp portion of the console log.
   */
  self.timestamp = function () {
    return "[" + Date() + "]";
  };

  /**
   * Logger methods
   * 
   * @type {Array}
   */
  var methods = [ 
    'debug', 'info', 'error', 'warn', 'assert', 'table', 'count', 'trace', 'dir', 'clear',
    'group', 'groupEnd', 'time', 'timeEnd'
  ];

  /**
   * Generation
   */
  
  (function next (index) {
    if (index < methods.length) {
      var method = methods[index];

      self[method] = function () {
        var alias = type(method, (method == 'debug' || method == 'info' || method == 'error' || method == 'warn'));

        if (environment == environments.TESTING) {
          return alias.apply(this, Array.prototype.slice.call(arguments));
        } else if (method == 'error' || method == 'warn') {
          return alias.apply(this, Array.prototype.slice.call(arguments));
        }

        return;
      };

      next(index + 1);
    }
  })(0);

  /**
   * Exposing the public interface to the log module
   * 
   * @private
   */
  return self;
};