Cleanup some code in nested_attributes.rb, autosave_association.rb, and...

Cleanup some code in nested_attributes.rb, autosave_association.rb, and associations.rb with AssociationReflection#collection_association?

Also cache the result value.

activerecord/lib/active_record/associations.rb

@@ -1770,7 +1770,7 @@ def construct_finder_sql_for_association_limiting(options, join_dependency)
         end
 
         def using_limitable_reflections?(reflections)
-          reflections.reject { |r| [ :belongs_to, :has_one ].include?(r.macro) }.length.zero?
+          reflections.collect(&:collection_association?).length.zero?
         end
 
         def column_aliases(join_dependency)
@@ -1843,7 +1843,7 @@ def remove_duplicate_results!(base, records, associations)
             case associations
               when Symbol, String
                 reflection = base.reflections[associations]
-                if reflection && [:has_many, :has_and_belongs_to_many].include?(reflection.macro)
+                if reflection && reflection.collection_association?
                   records.each { |record| record.send(reflection.name).target.uniq! }
                 end
               when Array
@@ -1853,12 +1853,11 @@ def remove_duplicate_results!(base, records, associations)
               when Hash
                 associations.keys.each do |name|
                   reflection = base.reflections[name]
-                  is_collection = [:has_many, :has_and_belongs_to_many].include?(reflection.macro)
 
                   parent_records = []
                   records.each do |record|
                     if descendant = record.send(reflection.name)
-                      if is_collection
+                      if reflection.collection_association?
                         parent_records.concat descendant.target.uniq
                       else
                         parent_records << descendant

activerecord/lib/active_record/autosave_association.rb

@@ -167,8 +167,7 @@ def add_autosave_association_callbacks(reflection)
         validation_method = "validate_associated_records_for_#{reflection.name}"
         force_validation = (reflection.options[:validate] == true || reflection.options[:autosave] == true)
 
-        case reflection.macro
-        when :has_many, :has_and_belongs_to_many
+        if reflection.collection_association?
           unless method_defined?(save_method)
             before_save :before_save_collection_association
 

activerecord/lib/active_record/nested_attributes.rb

@@ -235,16 +235,10 @@ def accepts_nested_attributes_for(*attr_names)
 
         attr_names.each do |association_name|
           if reflection = reflect_on_association(association_name)
-            type = case reflection.macro
-            when :has_one, :belongs_to
-              :one_to_one
-            when :has_many, :has_and_belongs_to_many
-              :collection
-            end
-
             reflection.options[:autosave] = true
             add_autosave_association_callbacks(reflection)
             nested_attributes_options[association_name.to_sym] = options
+            type = (reflection.collection_association? ? :collection : :one_to_one)
 
             # def pirate_attributes=(attributes)
             #   assign_nested_attributes_for_one_to_one_association(:pirate, attributes)

activerecord/lib/active_record/reflection.rb

@@ -256,7 +256,10 @@ def polymorphic_inverse_of(associated_class)
       # association. Returns +true+ if the +macro+ is one of +has_many+ or
       # +has_and_belongs_to_many+, +false+ otherwise.
       def collection_association?
-        [:has_many, :has_and_belongs_to_many].include?(macro)
+        if @collection_association.nil?
+          @collection_association = [:has_many, :has_and_belongs_to_many].include?(macro)
+        end
+        @collection_association
       end
 
       private