Add error message for case when schedule cannot be deleted

app/assets/javascripts/admin/order_cycles/directives/schedule_dialog.js.coffee

@@ -31,6 +31,13 @@ angular.module("admin.orderCycles").directive 'scheduleDialog', ($window, $compi
       if confirm(t('are_you_sure'))
         Schedules.remove(scope.schedule).$promise.then (data) ->
           scope.close()
+        , (response) ->
+          errors = response.data.errors
+          if errors?
+            scope.errors.push errors[0]
+          else
+            scope.errors.push "Could not delete schedule: #{scope.schedule.name}"
+
 
     scope.loadMore = ->
       scope.showMore().then ->

app/assets/javascripts/admin/resources/services/schedules.js.coffee

@@ -39,12 +39,6 @@ angular.module("admin.resources").factory "Schedules", ($q, $injector, RequestMo
             orderCycle.schedules.splice(i, 1) for s, i in orderCycle.schedules by -1 when s.id == schedule.id
         delete @byID[schedule.id]
         StatusMessage.display 'success', "#{t('admin.order_cycles.index.deleted_schedule')}: '#{schedule.name}'"
-      , (response) =>
-        errors = response.data.errors
-        if errors?
-          InfoDialog.open 'error', errors[0]
-        else
-          InfoDialog.open 'error', "Could not delete schedule: #{schedule.name}"
 
     index: ->
       request = ScheduleResource.index (data) => @load(data)

app/controllers/admin/schedules_controller.rb

@@ -4,6 +4,7 @@ require 'open_food_network/proxy_order_syncer'
 module Admin
   class SchedulesController < ResourceController
     before_filter :check_editable_order_cycle_ids, only: [:create, :update]
+    before_filter :check_dependent_subscriptions, only: [:destroy]
     create.after :sync_subscriptions
     update.after :sync_subscriptions
 
@@ -49,6 +50,11 @@ module Admin
       @object.order_cycle_ids = result
     end
 
+    def check_dependent_subscriptions
+      return if Subscription.where(schedule_id: @schedule).empty?
+      render json: { errors: [t('admin.schedules.destroy.associated_subscriptions_error')] }, status: :conflict
+    end
+
     def permissions
       return @permissions unless @permission.nil?
       @permissions = OpenFoodNetwork::Permissions.new(spree_current_user)

config/locales/en.yml

@@ -958,6 +958,10 @@ en:
         why_dont_you_add_one: Why don't you add one? :)
         no_matching_subscriptions: No matching subscriptions found
 
+    schedules:
+      destroy:
+        associated_subscriptions_error: This schedule cannot be deleted because it has associated subscriptions
+
     stripe_connect_settings:
       edit:
         title: "Stripe Connect"

spec/controllers/admin/schedules_controller_spec.rb

@@ -200,8 +200,20 @@ describe Admin::SchedulesController, type: :controller do
         context "where I manage at least one of the schedule's coordinators" do
           before { params.merge!(id: coordinated_schedule.id) }
 
-          it "allows me to destroy the schedule" do
-            expect { spree_delete :destroy, params }.to change(Schedule, :count).by(-1)
+          context "when no dependent subscriptions are present" do
+            it "allows me to destroy the schedule" do
+              expect { spree_delete :destroy, params }.to change(Schedule, :count).by(-1)
+            end
+          end
+
+          context "when a dependent subscription is present" do
+            let!(:subscription) { create(:subscription, schedule: coordinated_schedule) }
+
+            it "returns an error message and prevents me from deleting the schedule" do
+              expect { spree_delete :destroy, params }.to_not change(Schedule, :count)
+              json_response = JSON.parse(response.body)
+              expect(json_response["errors"]).to include I18n.t('admin.schedules.destroy.associated_subscriptions_error')
+            end
           end
         end