Fix comment - move method to model

app/helpers/cities_helper.rb

 module CitiesHelper
-  def get_city_by_area(area)
-    City.where(area: area)
-  end
 end

app/models/area.rb

@@ -2,4 +2,8 @@ class Area < ApplicationRecord
   has_many :city
 
   validates :name, presence: true
+
+  def self.get_city_by_area(area)
+    City.where(area: area)
+  end
 end

app/views/cities/show.html.erb

@@ -15,7 +15,7 @@
   <div class="well">
     <h3> <%= area.name %> </h3>
     <div class="row">
-      <%- get_city_by_area(area).each do |city| -%>
+      <%- Area.get_city_by_area(area).each do |city| -%>
         <%- if city.job.count > 0 -%>
           <div class="col-md-4">
             <%= link_to city.name, jobs_show_path(city_id: city.id) %>