Mirroring Rails Environment in Javascript

environment.js

// This should actually be a .js.erb file so you can interpolate Ruby code in it
// I left it off the file naming because the gist would color words weird when .js.erb
// was the file extension

;(function(window){
  var _environment;

  /*
   * Namespace. 
   * You could name this anything you want, even stick to rails conventions and do:
   *
   * ```javascript
   *     window.Rails = {};
   *     Rails.env = function(){};
   * ```
   *
   * It is important that this is a function. It gives us the option to attach other
   * methods to it, while still impersonating a string
   * 
   * @type Function !IMPORTANT
   */

  window.Environment = function() { 
    // Have it return the toString function as we override that later
    // to make it return the actual environment
    return this.toString(); 
  };


  /*
   * Our actual tracking of the environemnt variable. 
   * By making this a .js.erb file we can interpolate Ruby code and return the environment
   * string
   *
   * @type String
   */

  _environment = "<%= Rails.env %>";


  /*
   * Make the namespace function impersonate a string.
   * This override of `prototype.toString` makes it so consoling window.Environment will print
   * what we want, instead of the function definition
   */

  Environment.toString = function() {
    return environment;
  };


  /*
   * HELPER FUNCTIONS
   * Add any helper function you want for environment checks
   *
   * @return Boolean
   */

  Environment.isProduction = function(){
    return 'production' === environment;
  };

  Environment.isDevelopment = function(){
    return 'development' === environment
  }

})(window);