drying up construct_association

activerecord/lib/active_record/associations.rb

@@ -1978,27 +1978,27 @@ def construct(parent, associations, joins, row)
             def construct_association(record, join, row)
               return if record.id.to_s != join.parent.record_id(row).to_s
 
-              case join.reflection.macro
-              when :has_many, :has_and_belongs_to_many
-                collection = record.send(join.reflection.name)
-                collection.loaded
-
-                return if row[join.aliased_primary_key].nil?
-                association = join.instantiate(row)
-                collection.target.push(association)
-                collection.__send__(:set_inverse_instance, association, record)
-              when :has_one
+              macro = join.reflection.macro
+              if macro == :has_one
                 return if record.instance_variable_defined?("@#{join.reflection.name}")
                 association = join.instantiate(row) unless row[join.aliased_primary_key].nil?
                 set_target_and_inverse(join, association, record)
-              when :belongs_to
+              else
                 return if row[join.aliased_primary_key].nil?
                 association = join.instantiate(row)
-                set_target_and_inverse(join, association, record)
-              else
-                raise ConfigurationError, "unknown macro: #{join.reflection.macro}"
+                case macro
+                when :has_many, :has_and_belongs_to_many
+                  collection = record.send(join.reflection.name)
+                  collection.loaded
+                  collection.target.push(association)
+                  collection.__send__(:set_inverse_instance, association, record)
+                when :belongs_to
+                  set_target_and_inverse(join, association, record)
+                else
+                  raise ConfigurationError, "unknown macro: #{join.reflection.macro}"
+                end
               end
-              return association
+              association
             end
 
             def set_target_and_inverse(join, association, record)