Do not allow successful checkout when order has only a void payment

When a payment has been marked for some reason as `void`, the customer should
not be able to complete the checkout process successfully.

The customer is now redirected to the payment page, where they can add another
payment to the order in order to complete it successfully.

core/app/models/spree/payment.rb

@@ -58,7 +58,7 @@ class Payment < Spree::Base
     scope :failed, -> { with_state('failed') }
 
     scope :risky, -> { where("avs_response IN (?) OR (cvv_response_code IS NOT NULL and cvv_response_code != 'M') OR state = 'failed'", RISKY_AVS_CODES) }
-    scope :valid, -> { where.not(state: %w(failed invalid)) }
+    scope :valid, -> { where.not(state: %w(failed invalid void)) }
 
     scope :store_credits, -> { where(source_type: Spree::StoreCredit.to_s) }
     scope :not_store_credits, -> { where(arel_table[:source_type].not_eq(Spree::StoreCredit.to_s).or(arel_table[:source_type].eq(nil))) }

core/spec/models/spree/payment_spec.rb

@@ -1255,4 +1255,16 @@
       end
     end
   end
+
+  describe '::valid scope' do
+    before do
+      create :payment, state: :void
+      create :payment, state: :failed
+      create :payment, state: :invalid
+    end
+
+    it 'does not include void, failed and invalid payments' do
+      expect(described_class.valid).to be_empty
+    end
+  end
 end

frontend/spec/features/checkout_spec.rb

@@ -211,6 +211,26 @@
     end
   end
 
+  context "when order has only a void payment" do
+    let(:order) { Spree::TestingSupport::OrderWalkthrough.up_to(:payment) }
+
+    before do
+      user = create(:user)
+      order.user = user
+      order.recalculate
+
+      allow_any_instance_of(Spree::CheckoutController).to receive_messages(current_order: order)
+      allow_any_instance_of(Spree::CheckoutController).to receive_messages(try_spree_current_user: user)
+    end
+
+    it "does not allow successful order submission" do
+      visit spree.checkout_path
+      order.payments.first.update state: :void
+      click_button 'Place Order'
+      expect(page).to have_current_path spree.checkout_state_path(:payment)
+    end
+  end
+
   # Regression test for https://github.com/spree/spree/issues/2694 and https://github.com/spree/spree/issues/4117
   context "doesn't allow bad credit card numbers" do
     let!(:payment_method) { create(:credit_card_payment_method) }