provide render_label_sum

Gemfile

@@ -45,6 +45,7 @@ end
 if File.file? File.expand_path './.enable_test', __dir__
   group :development, :test do
     gem 'active_record_doctor', require: false
+    gem 'rails_best_practices', require: false
     gem 'bullet'
   end
   group :test do

app/views/mailer/_entity.html.slim

@@ -10,8 +10,5 @@ h1 = link_to h(title), entity_url
   fieldset.attachments
     legend = l :label_attachment_plural
     - entity.attachments.each do |attachment|
-      = link_to_attachment attachment, download: true, only_path: false
-      |  (
-      = number_to_human_size attachment.filesize
-      | )
+      = render_label_sum link_to_attachment(attachment, download: true, only_path: false), number_to_human_size(attachment.filesize)
       br

lib/additionals/helpers.rb

@@ -231,6 +231,11 @@ module Additionals
       end
     end
 
+    def render_label_sum(label, sum)
+      name = label.is_a?(Symbol) ? l(label) : label
+      "#{name} (#{sum})"
+    end
+
     private
 
     def additionals_already_loaded(scope, js_name)