1 files changed, 13 insertions, 44 deletions
diff --git a/activerecord/lib/active_record/associations/builder/has_one.rb b/activerecord/lib/active_record/associations/builder/has_one.rb
index bc8a212bee..0da564f402 100644
--- a/activerecord/lib/active_record/associations/builder/has_one.rb
+++ b/activerecord/lib/active_record/associations/builder/has_one.rb
@@ -1,56 +1,25 @@
-require 'active_support/core_ext/object/inclusion'
-
 module ActiveRecord::Associations::Builder
   class HasOne < SingularAssociation #:nodoc:
-    self.macro = :has_one
-
-    self.valid_options += [:order, :as]
+    def macro
+      :has_one
+    end
 
-    class_attribute :through_options
-    self.through_options = [:through, :source, :source_type]
+    def valid_options
+      valid = super + [:order, :as]
+      valid += [:through, :source, :source_type] if options[:through]
+      valid
+    end
 
     def constructable?
       !options[:through]
     end
 
-    def build
-      reflection = super
-      configure_dependency unless options[:through]
-      reflection
+    def configure_dependency
+      super unless options[:through]
     end
 
-    private
-
-      def validate_options
-        valid_options = self.class.valid_options
-        valid_options += self.class.through_options if options[:through]
-        options.assert_valid_keys(valid_options)
-      end
-
-      def configure_dependency
-        if options[:dependent]
-          unless options[:dependent].in?([:destroy, :delete, :nullify, :restrict])
-            raise ArgumentError, "The :dependent option expects either :destroy, :delete, " \
-                                 ":nullify or :restrict (#{options[:dependent].inspect})"
-          end
-
-          dependent_restrict_deprecation_warning if options[:dependent] == :restrict
-          send("define_#{options[:dependent]}_dependency_method")
-          model.before_destroy dependency_method_name
-        end
-      end
-
-      def define_destroy_dependency_method
-        name = self.name
-        mixin.redefine_method(dependency_method_name) do
-          association(name).delete
-        end
-      end
-      alias :define_delete_dependency_method :define_destroy_dependency_method
-      alias :define_nullify_dependency_method :define_destroy_dependency_method
-
-      def dependency_method_name
-        "has_one_dependent_#{options[:dependent]}_for_#{name}"
-      end
+    def valid_dependent_options
+      [:destroy, :delete, :nullify, :restrict, :restrict_with_error, :restrict_with_exception]
+    end
   end
 end