Attempt to spec for error

I'm trying to replicate issue openfoodfoundation#12693, but am not sure how to.
Hmm, maybe it should be mocking an exception during payment, which causes the rollback.

app/controllers/checkout_controller.rb

@@ -68,6 +68,8 @@ def check_payments_adjustments
 
   def clear_invalid_payments
     @order.payments.with_state(:invalid).delete_all
+    # todo: delete all invalid payments, and somehow remove them from the association without reloading any valid payments?
+    #  how about loop through them, delete and reload one by one.
   end
 
   def confirm_order

spec/controllers/checkout_controller_spec.rb

@@ -306,6 +306,23 @@
             expect(response).to redirect_to checkout_step_path(:summary)
           end
         end
+
+        context "with existing invalid payments" do
+          let(:invalid_payments) { [
+              create(:payment, state: :failed),
+              create(:payment, state: :void),
+            ] }
+
+          before do
+            order.payments = invalid_payments
+          end
+
+          it "deletes invalid payments" do
+            expect{
+              put(:update, params:)
+            }.to change { order.payments.to_a }.from(invalid_payments)
+          end
+        end
       end
 
       context "with no payment source" do