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

[#2797 state:committed]

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

3 files changed, 7 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index c4d143ab05..1fc0c93732 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/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
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index a7be3539d5..467d955a49 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/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
diff --git a/activerecord/lib/active_record/named_scope.rb b/activerecord/lib/active_record/named_scope.rb
index 1b22fa5e24..dd2a90b8e5 100644
--- a/activerecord/lib/active_record/named_scope.rb
+++ b/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