1 files changed, 31 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/associations/singular_association.rb b/activerecord/lib/active_record/associations/singular_association.rb
new file mode 100644
index 0000000000..023f7caf68
--- /dev/null
+++ b/activerecord/lib/active_record/associations/singular_association.rb
@@ -0,0 +1,31 @@
+module ActiveRecord
+  module Associations
+    class SingularAssociation < AssociationProxy #:nodoc:
+      def create(attributes = {})
+        record = scoped.scoping { @reflection.create_association(attributes) }
+        set_new_record(record)
+        record
+      end
+
+      def create!(attributes = {})
+        build(attributes).tap { |record| record.save! }
+      end
+
+      def build(attributes = {})
+        record = scoped.scoping { @reflection.build_association(attributes) }
+        set_new_record(record)
+        record
+      end
+
+      private
+        # Implemented by subclasses
+        def replace(record)
+          raise NotImplementedError
+        end
+
+        def set_new_record(record)
+          replace(record)
+        end
+    end
+  end
+end