Fix bug where shipments by LP provider with wrong size received discounts

lib/planet_express/rules/l_shipment_discount_rule.rb

@@ -6,6 +6,7 @@ module PlanetExpress
 
     def applicable_to?(shipment)
       lp_provider_shipment?(shipment) &&
+        l_shipment?(shipment) &&
         third_l_shipment_in_month?(shipment) &&
         rule_not_applied_in_month_already?(shipment)
     end
@@ -16,6 +17,10 @@ module PlanetExpress
 
     private
 
+    def l_shipment?(shipment)
+      shipment.l_shipment?
+    end
+
     def lp_provider_shipment?(shipment)
       shipment.lp_provider?
     end
@@ -26,7 +31,7 @@ module PlanetExpress
 
       count = shipment_repository.l_shipment_count_for_provider_and_month(provider,
                                                                           month)
-      (count % 3) == 2
+      count == 2
     end
 
     def rule_not_applied_in_month_already?(shipment)

spec/l_shipment_discount_rule_spec.rb

@@ -73,6 +73,25 @@ RSpec.describe PlanetExpress::LShipmentDiscountRule do
           end.to_not(change { shipment.discounts })
         end
       end
+
+      context 'non L shipment' do
+        before(:each) do
+          shipment_repo.add(applicable_shipment)
+          shipment_repo.add(applicable_shipment)
+        end
+        let(:shipping_option) do
+          shipping_option_repo.find_by_provider_and_package_size('LP', 'M')
+        end
+        let(:shipment) do
+          PlanetExpress::Shipment.new(Date.today, shipping_option)
+        end
+
+        it 'does not update the discounts' do
+          expect do
+            subject.apply_to(shipment)
+          end.to_not(change { shipment.discounts })
+        end
+      end
     end
   end
 end