add eligibility checking to automatic free shipping promotions

core/app/models/spree/promotion_handler/shipping.rb

@@ -18,7 +18,9 @@ def activate
         end
 
         not_connected_automatic_promotions.each do |promotion|
-          promotion.activate(order: order)
+          if promotion.eligible?(order)
+            promotion.activate(order: order)
+          end
         end
       end
 

core/spec/models/spree/promotion_handler/shipping_spec.rb

@@ -13,8 +13,20 @@ module PromotionHandler
       context 'with apply_automatically' do
         let!(:promotion) { create(:promotion, apply_automatically: true, promotion_actions: [action]) }
 
-        it "creates the adjustment" do
-          expect { subject.activate }.to change { shipment.adjustments.count }.by(1)
+        context 'for eligible promotion' do
+          it "creates the adjustment" do
+            expect { subject.activate }.to change { shipment.adjustments.count }.by(1)
+          end
+        end
+
+        context 'for ineligible promotion' do
+          let!(:promotion) do
+            create(:promotion, :with_item_total_rule, item_total_threshold_amount: 1_000, apply_automatically: true, promotion_actions: [action])
+          end
+
+          it "does not create the adjustment" do
+            expect { subject.activate }.to change { shipment.adjustments.count }.by(0)
+          end
         end
       end