Index variants by id

app/models/spree/variant_decorator.rb

@@ -46,6 +46,13 @@ Spree::Variant.class_eval do
   }
 
 
+  def self.indexed
+    Hash[
+      scoped.map { |v| [v.id, v] }
+    ]
+  end
+
+
   def price_with_fees(distributor, order_cycle)
     price + fees_for(distributor, order_cycle)
   end

spec/models/spree/variant_spec.rb

@@ -104,6 +104,17 @@ module Spree
       end
     end
 
+    describe "indexing variants by id" do
+      let!(:v1) { create(:variant) }
+      let!(:v2) { create(:variant) }
+      let!(:v3) { create(:variant) }
+
+      it "indexes variants by id" do
+        Variant.where(id: [v1, v2, v3]).indexed.should ==
+          {v1.id => v1, v2.id => v2, v3.id => v3}
+      end
+    end
+
     describe "generating the full name" do
       let(:v) { Variant.new }