uses Object#metaclass and Object#class_eval in a few spots

[#2797 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

actionpack/lib/action_controller/testing/integration.rb

@@ -1,6 +1,7 @@
 require 'stringio'
 require 'uri'
 require 'active_support/test_case'
+require 'active_support/core_ext/object/metaclass'
 
 require 'rack/mock_session'
 require 'rack/test/cookie_jar'
@@ -191,7 +192,7 @@ module ActionController
 
         unless defined? @named_routes_configured
           # install the named routes in this session instance.
-          klass = class << self; self; end
+          klass = metaclass
           Routing::Routes.install_helpers(klass)
 
           # the helpers are made protected by default--we make them public for

activerecord/lib/active_record/base.rb

@@ -11,6 +11,7 @@ require 'active_support/core_ext/hash/indifferent_access'
 require 'active_support/core_ext/hash/slice'
 require 'active_support/core_ext/string/behavior'
 require 'active_support/core_ext/symbol'
+require 'active_support/core_ext/object/metaclass'
 
 module ActiveRecord #:nodoc:
   # Generic Active Record exception class.
@@ -2040,7 +2041,7 @@ module ActiveRecord #:nodoc:
         #     end
         #   end
         def define_attr_method(name, value=nil, &block)
-          sing = class << self; self; end
+          sing = metaclass
           sing.send :alias_method, "original_#{name}", name
           if block_given?
             sing.send :define_method, name, &block

activerecord/lib/active_record/migration.rb

@@ -1,3 +1,5 @@
+require 'active_support/core_ext/object/metaclass'
+
 module ActiveRecord
   class IrreversibleMigration < ActiveRecordError#:nodoc:
   end
@@ -300,8 +302,7 @@ module ActiveRecord
 
           case sym
             when :up, :down
-              klass = (class << self; self; end)
-              klass.send(:alias_method_chain, sym, "benchmarks")
+              metaclass.send(:alias_method_chain, sym, "benchmarks")
           end
         ensure
           @ignore_new_methods = false

activerecord/lib/active_record/named_scope.rb

@@ -1,5 +1,6 @@
 require 'active_support/core_ext/array'
 require 'active_support/core_ext/hash/except'
+require 'active_support/core_ext/object/metaclass'
 
 module ActiveRecord
   module NamedScope
@@ -99,7 +100,7 @@ module ActiveRecord
               end
           end, &block)
         end
-        (class << self; self end).instance_eval do
+        metaclass.instance_eval do
           define_method name do |*args|
             scopes[name].call(self, *args)
           end

activesupport/lib/active_support/core_ext/proc.rb

@@ -1,7 +1,7 @@
 class Proc #:nodoc:
   def bind(object)
     block, time = self, Time.now
-    (class << object; self end).class_eval do
+    object.class_eval do
       method_name = "__bind_#{time.to_i}_#{time.usec}"
       define_method(method_name, &block)     # define_method("__bind_1230458026_720454", &block)
       method = instance_method(method_name)  # method = instance_method("__bind_1230458026_720454")

activesupport/lib/active_support/new_callbacks.rb

@@ -307,7 +307,7 @@ module ActiveSupport
 
       def _normalize_legacy_filter(kind, filter)
         if !filter.respond_to?(kind) && filter.respond_to?(:filter)
-          filter.metaclass.class_eval(
+          filter.class_eval(
             "def #{kind}(context, &block) filter(context, &block) end",
             __FILE__, __LINE__ - 1)
         elsif filter.respond_to?(:before) && filter.respond_to?(:after) && kind == :around