Unpublish draft worldwide office when deleted

If a worldwide office is attached to a draft editionable worldwide
organisation and the office itself is deleted, we need to unpublish the
draft office and it's contact from Publishing API.

This cannot be done using `PublishingApiAssociatedDocuments` as
worldwide offices are hard deleted and therefore we can't use a query to
identify which offices have been deleted, like we can for HTML
attachments.

app/controllers/admin/worldwide_offices_controller.rb

@@ -50,6 +50,11 @@ def destroy
     title = @worldwide_office.title
 
     if @worldwide_office.destroy
+      if @worldwide_office.edition
+        PublishingApiDiscardDraftWorker.perform_async(@worldwide_office.content_id, I18n.default_locale.to_s)
+        PublishingApiDiscardDraftWorker.perform_async(@worldwide_office.contact.content_id, I18n.default_locale.to_s)
+      end
+
       republish_draft_worldwide_organisation
       redirect_to admin_worldwide_organisation_worldwide_offices_path(@worldwide_organisation), notice: "#{title} has been deleted"
     else

test/functional/admin/worldwide_offices_controller_test.rb

@@ -440,6 +440,23 @@ class Admin::WorldwideOfficesControllerTest < ActionController::TestCase
            }
   end
 
+  test "DELETE :destroy for an office attached to an editionable worldwide organisation discards draft of the office and the contact" do
+    feature_flags.switch! :editionable_worldwide_organisations, true
+
+    office = create(:worldwide_office, edition: create(:draft_editionable_worldwide_organisation), worldwide_organisation: nil)
+
+    PublishingApiDiscardDraftWorker.any_instance.expects(:perform).with(office.content_id, "en")
+    PublishingApiDiscardDraftWorker.any_instance.expects(:perform).with(office.contact.content_id, "en")
+
+    Sidekiq::Testing.inline! do
+      delete :destroy,
+             params: {
+               id: office,
+               worldwide_organisation_id: office.edition,
+             }
+    end
+  end
+
 private
 
   def create_worldwide_organisation_and_office