Fix Rubocop offenses

Author: MrSerth

app/controllers/concerns/redirect_behavior.rb

@@ -74,7 +74,7 @@ def redirect_to_user_feedback
 
   def redirect_to_unsolved_rfc(own: false)
     # Set a message that informs the user that their own RFC should be closed or help in another RFC is greatly appreciated.
-    flash[:notice] = I18n.t("exercises.editor.exercise_finished_redirect_to_#{own ? 'own_' : ''}rfc")
+    flash[:notice] = I18n.t("exercises.editor.exercise_finished_redirect_to_#{'own_' if own}rfc")
     flash.keep(:notice)
 
     # Increase counter 'times_featured' in rfc

app/controllers/external_users_controller.rb

@@ -60,7 +60,7 @@ def working_time_query(tag = nil)
                    filtered_submissions.created_at
           ) AS foo
       ) AS bar
-    #{tag.nil? ? '' : " JOIN exercise_tags et ON et.exercise_id = bar.exercise_id AND #{ExternalUser.sanitize_sql(['et.tag_id = ?', tag])}"}
+    #{" JOIN exercise_tags et ON et.exercise_id = bar.exercise_id AND #{ExternalUser.sanitize_sql(['et.tag_id = ?', tag])}" unless tag.nil?}
     GROUP BY contributor_id,
              bar.exercise_id;
     "

app/policies/application_policy.rb

@@ -16,13 +16,13 @@ def author?
   end
   private :author?
 
-  def everyone
+  def everyone # rubocop:disable Naming/PredicateMethod
     # As the ApplicationController forces to have any authorization, `everyone` here means `every user logged in`
     true
   end
   private :everyone
 
-  def no_one
+  def no_one # rubocop:disable Naming/PredicateMethod
     false
   end
   private :no_one

app/views/execution_environments/statistics.html.slim

@@ -26,7 +26,7 @@ h1 = @execution_environment
           td = us['average_score'].to_f.round(4)
           td = us['maximum_score'].to_f.round(2)
           td = us['stddev_score'].to_f.round(4)
-          td = (us['percent_correct'].to_f || 0).round(4)
+          td = us['percent_correct'].to_f.round(4)
           td = us['average_submission_count'].to_f.round(2)
           td = average_time
           td = stddev_time

lib/code_ocean/config.rb

@@ -5,7 +5,7 @@ class Config
     attr_reader :path, :read
 
     def initialize(filename, options = {})
-      @path = Rails.root.join('config', "#{filename}.yml#{options[:erb] ? '.erb' : ''}")
+      @path = Rails.root.join('config', "#{filename}.yml#{'.erb' if options[:erb]}")
       @read = parse(options)
     end
 

lib/runner/strategy/null.rb

@@ -45,7 +45,7 @@ def self.available_images
 
   def self.config; end
 
-  def self.health
+  def self.health # rubocop:disable Naming/PredicateMethod
     true
   end