Use application finder for Doorkeeper Applications

app/finders/applications_finder.rb

+# frozen_string_literal: true
+
+class ApplicationsFinder
+  attr_reader :params
+
+  def initialize(params = {})
+    @params = params
+  end
+
+  # rubocop: disable CodeReuse/ActiveRecord
+  def execute
+    applications = Doorkeeper::Application.where("owner_id IS NULL")
+    by_id(applications)
+  end
+  # rubocop: enable CodeReuse/ActiveRecord
+
+  private
+
+  # rubocop: disable CodeReuse/ActiveRecord
+  def by_id(applications)
+    return applications unless params[:id]
+
+    Doorkeeper::Application.find_by(id: params[:id])
+  end
+  # rubocop: enable CodeReuse/ActiveRecord
+end

lib/api/applications.rb

@@ -25,24 +25,21 @@ module API
         end
       end
 
-      # rubocop: disable CodeReuse/ActiveRecord
       desc 'Get applications' do
         success Entities::Application
       end
       get do
-        applications = Doorkeeper::Application.where("owner_id IS NULL")
+        applications = ApplicationsFinder.new.execute
         present applications, with: Entities::Application
       end
-      # rubocop: enable CodeReuse/ActiveRecord
 
-      # rubocop: disable CodeReuse/ActiveRecord
       desc 'Delete an application'
       delete ':id' do
-        Doorkeeper::Application.find_by(id: params[:id]).destroy
+        application = ApplicationsFinder.new(params).execute
+        application.destroy
 
         status 204
       end
-      # rubocop: enable CodeReuse/ActiveRecord
     end
   end
 end