Get rid of the underscore versions of attribute methods!

This makes me happy!

5 files changed, 35 insertions, 6 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index bf28cffbbe..978e415e58 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -93,6 +93,7 @@ module ActiveRecord
       autoload :TimeZoneConversion
       autoload :Write
       autoload :Serialization
+      autoload :DeprecatedUnderscoreRead
     end
   end
 
diff --git a/activerecord/lib/active_record/attribute_methods/deprecated_underscore_read.rb b/activerecord/lib/active_record/attribute_methods/deprecated_underscore_read.rb
new file mode 100644
index 0000000000..0eb0db65b1
--- /dev/null
+++ b/activerecord/lib/active_record/attribute_methods/deprecated_underscore_read.rb
@@ -0,0 +1,32 @@
+require 'active_support/concern'
+require 'active_support/deprecation'
+
+module ActiveRecord
+  module AttributeMethods
+    module DeprecatedUnderscoreRead
+      extend ActiveSupport::Concern
+
+      included do
+        attribute_method_prefix "_"
+      end
+
+      module ClassMethods
+        protected
+
+        def define_method__attribute(attr_name)
+          # Do nothing, let it hit method missing instead.
+        end
+      end
+
+      protected
+
+      def _attribute(attr_name)
+        ActiveSupport::Deprecation.warn(
+          "You have called '_#{attr_name}'. This is deprecated. Please use " \
+          "either '#{attr_name}' or read_attribute('#{attr_name}')."
+        )
+        read_attribute(attr_name)
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index 6eff716703..98aa1ed225 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -13,7 +13,6 @@ module ActiveRecord
       def id
         read_attribute(self.class.primary_key)
       end
-      alias _id id
 
       # Sets the primary key value
       def id=(value)
@@ -27,7 +26,7 @@ module ActiveRecord
 
       module ClassMethods
         def dangerous_attribute_method?(method_name)
-          super && !['id', 'id=', 'id?', '_id'].include?(method_name)
+          super && !['id', 'id=', 'id?'].include?(method_name)
         end
 
         # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 59e57135f9..8eec06302a 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -61,8 +61,6 @@ module ActiveRecord
                 def self.cast_#{attr_name}(v)
                   #{cast_code}
                 end
-
-                alias _#{attr_name} #{attr_name}
               STR
             else
               generated_attribute_methods.module_eval do
@@ -73,8 +71,6 @@ module ActiveRecord
                 singleton_class.send(:define_method, "cast_#{attr_name}") do |v|
                   eval(cast_code)
                 end
-
-                alias_method("_#{attr_name}", attr_name)
               end
             end
           end
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 76aa121ade..6ba571a632 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -2200,6 +2200,7 @@ MSG
     include AttributeMethods::TimeZoneConversion
     include AttributeMethods::Dirty
     include AttributeMethods::Serialization
+    include AttributeMethods::DeprecatedUnderscoreRead
     include ActiveModel::MassAssignmentSecurity
     include Callbacks, ActiveModel::Observing, Timestamp
     include Associations, NamedScope