Add LineItem#supplied_by scope, fixes orders and fulfillment report supplier filtering

app/models/spree/line_item_decorator.rb

@@ -13,4 +13,9 @@ Spree::LineItem.class_eval do
       select('spree_line_items.*')
     end
   }
+
+  scope :supplied_by, lambda { |enterprise|
+    joins(:product).
+    where('spree_products.supplier_id = ?', enterprise)
+  }
 end

spec/models/line_item_spec.rb

@@ -2,5 +2,22 @@ require 'spec_helper'
 
 module Spree
   describe LineItem do
+    describe "scopes" do
+      it "finds line items for products supplied by a particular enterprise" do
+        o = create(:order)
+
+        s1 = create(:supplier_enterprise)
+        s2 = create(:supplier_enterprise)
+
+        p1 = create(:simple_product, supplier: s1)
+        p2 = create(:simple_product, supplier: s2)
+
+        li1 = create(:line_item, order: o, product: p1)
+        li2 = create(:line_item, order: o, product: p2)
+
+        LineItem.supplied_by(s1).should == [li1]
+        LineItem.supplied_by(s2).should == [li2]
+      end
+    end
   end
 end