Extend angular promises with success and error

extended_promises.js

(function(){
  'use strict';
  
  angular.module("app", [])
  
  // config phase  
  .config(function ($provide) {
    
    // decorate the $q service
    $provide.decorator('$q', function decorateQ($delegate) {
      
      // refer to original defer method
      var defer = $delegate.defer;
      
      // monkey patch the method
      $delegate.defer = function () {
        var deferred = defer();
        
        // success method
        deferred.promise.success = function (fn) {
          deferred.promise.then(fn);
          return deferred.promise;
        };
        
        // error method
        deferred.promise.error = function (fn) {
          deferred.promise.then(null, fn);
          return deferred.promise;
        };
        return deferred;
      };
      
      // return patched service
      return $delegate;
    });
  
  });
})()