Don't monkey-patch Hash anymore, to solve ActiveSupport conflicts.

lib/gattica.rb

@@ -12,7 +12,7 @@
 
 # internal
 require 'gattica/version'
-require 'gattica/core_extensions'
+require 'gattica/hash_extensions'
 require 'gattica/convertible'
 require 'gattica/exceptions'
 require 'gattica/user'

lib/gattica/auth.rb

@@ -18,6 +18,7 @@ class Auth
     # Try to authenticate the user
     def initialize(http, user)
       options = OPTIONS.merge(user.to_h)
+      options.extend HashExtensions
 
       response, data = http.post(SCRIPT_NAME, options.to_query, HEADERS)
       if response.code != '200'

lib/gattica/convertible.rb

@@ -10,7 +10,7 @@ def to_h
       instance_variables.each do |var|
         output.merge!({ var[1..-1] => instance_variable_get(var) }) unless var == '@xml'    # exclude the whole XML dump
       end
-      output
+      output.tap { |h| h.include HashExtensions }
     end
 
     # output nice inspect syntax

lib/gattica/hash_extensions.rb

@@ -0,0 +1,20 @@
+module Gattica
+  module HashExtensions
+
+    def to_query
+      require 'cgi' unless defined?(CGI) && defined?(CGI::escape)
+      self.collect do |key, value|
+        "#{CGI.escape(key.to_s)}=#{CGI.escape(value.to_s)}"
+      end.sort * '&'
+    end
+
+    def key
+      self.keys.first if self.length == 1
+    end
+
+    def value
+      self.values.first if self.length == 1
+    end
+
+  end
+end