Show more helpful payment processing error in checkout

app/models/spree/order_decorator.rb

@@ -293,6 +293,24 @@ Spree::Order.class_eval do
     complete? && distributor.andand.allow_order_changes? && order_cycle.andand.open?
   end
 
+  # Override of existing Spree method. Can remove when we reach 2-0-stable
+  # See commit: https://github.com/spree/spree/commit/5fca58f658273451193d5711081d018c317814ed
+  # Allows GatewayError to show useful error messages in checkout
+  def process_payments!
+    pending_payments.each do |payment|
+      break if payment_total >= total
+
+      payment.process!
+
+      if payment.completed?
+        self.payment_total += payment.amount
+      end
+    end
+  rescue Spree::Core::GatewayError => e # This section changed
+    result = !!Spree::Config[:allow_checkout_on_gateway_error]
+    errors.add(:base, e.message) and return result
+  end
+
   private
 
   def shipping_address_from_distributor

spec/requests/stripe_connect_checkout_spec.rb

@@ -68,7 +68,7 @@ describe "Submitting Stripe Connect charge requests", type: :request do
           put update_checkout_path, params
           expect(response.status).to be 400
           json_response = JSON.parse(response.body)
-          expect(json_response["flash"]["error"]).to eq I18n.t(:payment_processing_failed)
+          expect(json_response["flash"]["error"]).to eq "Bup-bow..."
           expect(order.payments.completed.count).to be 0
         end
       end
@@ -128,7 +128,7 @@ describe "Submitting Stripe Connect charge requests", type: :request do
           put update_checkout_path, params
           expect(response.status).to be 400
           json_response = JSON.parse(response.body)
-          expect(json_response["flash"]["error"]).to eq I18n.t(:payment_processing_failed)
+          expect(json_response["flash"]["error"]).to eq "Bup-bow..."
           expect(order.payments.completed.count).to be 0
         end
       end
@@ -147,7 +147,7 @@ describe "Submitting Stripe Connect charge requests", type: :request do
           put update_checkout_path, params
           expect(response.status).to be 400
           json_response = JSON.parse(response.body)
-          expect(json_response["flash"]["error"]).to eq I18n.t(:payment_processing_failed)
+          expect(json_response["flash"]["error"]).to eq "Bup-bow..."
           expect(order.payments.completed.count).to be 0
         end
       end
@@ -209,7 +209,7 @@ describe "Submitting Stripe Connect charge requests", type: :request do
         put update_checkout_path, params
         expect(response.status).to be 400
         json_response = JSON.parse(response.body)
-        expect(json_response["flash"]["error"]).to eq I18n.t(:payment_processing_failed)
+        expect(json_response["flash"]["error"]).to eq "Bup-bow..."
         expect(order.payments.completed.count).to be 0
       end
     end
@@ -228,7 +228,7 @@ describe "Submitting Stripe Connect charge requests", type: :request do
         put update_checkout_path, params
         expect(response.status).to be 400
         json_response = JSON.parse(response.body)
-        expect(json_response["flash"]["error"]).to eq I18n.t(:payment_processing_failed)
+        expect(json_response["flash"]["error"]).to eq "Bup-bow..."
         expect(order.payments.completed.count).to be 0
       end
     end