Change template for checkout controller

Remove state machine exception rescue as it is now rescued from Api/BaseController

api/app/controllers/spree/api/checkouts_controller.rb

@@ -23,9 +23,6 @@ def next
         authorize! :update, @order, order_token
         @order.next!
         respond_with(@order, default_template: 'spree/api/orders/show', status: 200)
-      rescue StateMachines::InvalidTransition => error
-        logger.error("invalid_transition #{error.event} from #{error.from} for #{error.object.class.name}. Error: #{error.inspect}")
-        respond_with(@order, default_template: 'spree/api/orders/could_not_transition', status: 422)
       end
 
       def advance
@@ -42,9 +39,6 @@ def complete
           @order.complete!
           respond_with(@order, default_template: 'spree/api/orders/show', status: 200)
         end
-      rescue StateMachines::InvalidTransition => error
-        logger.error("invalid_transition #{error.event} from #{error.from} for #{error.object.class.name}. Error: #{error.inspect}")
-        respond_with(@order, default_template: 'spree/api/orders/could_not_transition', status: 422)
       end
 
       def update
@@ -57,12 +51,9 @@ def update
 
           return if after_update_attributes
 
-          if @order.completed? || @order.next
+          if @order.completed? || @order.next!
             state_callback(:after)
             respond_with(@order, default_template: 'spree/api/orders/show')
-          else
-            logger.error("failed_to_transition_errors=#{@order.errors.full_messages}")
-            respond_with(@order, default_template: 'spree/api/orders/could_not_transition', status: 422)
           end
         else
           invalid_resource!(@order)

api/spec/requests/spree/api/checkouts_controller_spec.rb

@@ -388,7 +388,6 @@ module Spree
           state: 'address',
           email: nil
         )
-
         put spree.next_api_checkout_path(order), params: { id: order.to_param, order_token: order.guest_token }
         expect(response.status).to eq(422)
         expect(json_response['error']).to match(/could not be transitioned/)
@@ -431,6 +430,19 @@ module Spree
             expect(json_response['errors']['expected_total']).to include(I18n.t('spree.api.order.expected_total_mismatch'))
           end
         end
+
+        context 'when cannot complete' do
+          let(:order) { create(:order) }
+
+          before { order.update(state: 'cart') }
+
+          it 'returns a state machine error' do
+            subject
+
+            expect(json_response['error']).to eq(I18n.t(:could_not_transition, scope: "spree.api", resource: 'order'))
+            expect(response.status).to eq(422)
+          end
+        end
       end
     end