Added toplevel scope for crops without a parent

app/models/crop.rb

@@ -14,6 +14,7 @@ class Crop < ActiveRecord::Base
 
   default_scope order("lower(system_name) asc")
   scope :recent, reorder("created_at desc")
+  scope :toplevel, where(:parent_id => nil)
   scope :randomized, reorder('random()') # ok on sqlite and psql, but not on mysql
 
   validates :en_wikipedia_url,

spec/models/crop_spec.rb

@@ -81,6 +81,12 @@ describe Crop do
       @roma.parent.should eq @tomato
       @tomato.varieties.should eq [@roma]
     end
+
+    it 'toplevel scope works' do
+      @tomato = FactoryGirl.create(:tomato)
+      @roma = FactoryGirl.create(:roma, :parent_id => @tomato.id)
+      Crop.toplevel.should eq [ @tomato ]
+    end
   end
 
   context 'photos' do