Use inheritance to avoid special-case code for the 'id' method

4 files changed, 21 insertions, 9 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index a5c2849844..16362acfe9 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -9,7 +9,27 @@ module ActiveRecord
         [key] if key
       end
 
+      # Returns the primary key value
+      def id
+        read_attribute(self.class.primary_key)
+      end
+      alias _id id
+
+      # Sets the primary key value
+      def id=(value)
+        write_attribute(self.class.primary_key, value)
+      end
+
+      # Queries the primary key value
+      def id?
+        query_attribute(self.class.primary_key)
+      end
+
       module ClassMethods
+        def dangerous_attribute_method?(method_name)
+          super && !['id', 'id=', 'id?', '_id'].include?(method_name)
+        end
+
         # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
         # primary_key_prefix_type setting, though.
         def primary_key
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 4a5afcd585..78dbbeb0e6 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -39,10 +39,6 @@ module ActiveRecord
             else
               define_read_method(attr_name, attr_name, columns_hash[attr_name])
             end
-
-            if attr_name == primary_key && attr_name != "id"
-              define_read_method('id', attr_name, columns_hash[attr_name])
-            end
           end
 
         private
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index eb585ee906..b605c09889 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -17,10 +17,6 @@ module ActiveRecord
                 write_attribute(attr_name, new_value)
               end
             end
-
-            if attr_name == primary_key && attr_name != "id"
-              generated_attribute_methods.module_eval("alias :id= :'#{primary_key}='")
-            end
           end
       end
 
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index 9300c57819..0327e5aea8 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -675,7 +675,7 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     topic = Topic.new(:id => 5)
     topic.id = 5
 
-    topic.method(:id).owner.send(:remove_method, :id)
+    topic.method(:id).owner.send(:undef_method, :id)
 
     assert_deprecated do
       assert_equal 5, topic.id