Allow to build plural transient associations

lib/cocoon/view_helpers.rb

@@ -102,8 +102,8 @@ module Cocoon
     private
 
     def create_object_on_non_association(f, association)
-      builder_method = "build_#{association}"
-      return f.object.send(builder_method) if f.object.respond_to?(builder_method)
+      builder_method = %W{build_#{association} build_#{association.to_s.singularize}}.select { |m| f.object.respond_to?(m) }.first
+      return f.object.send(builder_method) if builder_method
       raise "Association #{association} doesn't exist on #{f.object.class}"
     end
 

spec/cocoon_spec.rb

@@ -201,6 +201,12 @@ describe Cocoon do
         object.should_receive(:build_custom_item).and_return 'custom'
         @tester.create_object(stub(:object => object), :custom_item).should == 'custom'
       end
+
+      it "should create an association if object responds to 'build_association' as plural" do
+        object = Comment.new
+        object.should_receive(:build_custom_item).and_return 'custom'
+        @tester.create_object(stub(:object => object), :custom_items).should == 'custom'
+      end
     end
 
     context "get_partial_path" do