Consolidate html page title output logic into helper (#27563)

app/helpers/application_helper.rb

@@ -91,6 +91,14 @@ module ApplicationHelper
     end
   end
 
+  def html_title
+    safe_join(
+      [content_for(:page_title).to_s.chomp, title]
+      .select(&:present?),
+      ' - '
+    )
+  end
+
   def title
     Rails.env.production? ? site_title : "#{site_title} (Dev)"
   end

app/views/layouts/application.html.haml

@@ -24,7 +24,7 @@
     %meta{ name: 'theme-color', content: '#191b22' }/
     %meta{ name: 'apple-mobile-web-app-capable', content: 'yes' }/
 
-    %title= content_for?(:page_title) ? safe_join([yield(:page_title).chomp.html_safe, title], ' - ') : title
+    %title= html_title
 
     = stylesheet_pack_tag 'common', media: 'all', crossorigin: 'anonymous'
     = stylesheet_pack_tag current_theme, media: 'all', crossorigin: 'anonymous'