Nettoyage des appels map, pour utiliser la syntaxe &:

app/controllers/tags_controller.rb

@@ -2,7 +2,7 @@
 class TagsController < InheritedResources::Base
   def index
     @tags = Event
-      .pluck(:tags).map { |e| e.split }.flatten
+      .pluck(:tags).map(&:split).flatten
       .group_by { |i| i }
       .map { |k, v| [k, v.size] }
       .reject { |_k, v| v < 2 }

app/helpers/events_helper.rb

@@ -3,7 +3,7 @@ module EventsHelper
   def set_events_meta
     set_meta_tags \
       description: t('layouts.application.subtitle'),
-      keywords: @events.map { |e| e.tags }.join(' ').split.group_by { |i| i }
+      keywords: @events.map(&:tags).join(' ').split.group_by { |i| i }
         .reject { |_k, v| v.size < 2 }.map { |k, _v| k },
       DC: {
         title: t('layouts.application.title'),