Proc style, redundant returns

.rubocop.yml

   Exclude:
     - 'db/seeds.rb'
 
-# Offense count: 5
-# Cop supports --auto-correct.
-# Configuration parameters: AllowMultipleReturnValues.
-Style/RedundantReturn:
-  Exclude:
-    - 'app/helpers/authentication_helper.rb'
-    - 'app/models/activity.rb'
-    - 'app/models/person.rb'
-
 # Offense count: 85
 # Cop supports --auto-correct.
 Style/RedundantSelf:
 Style/SymbolArray:
   EnforcedStyle: brackets
 
-# Offense count: 5
-# Cop supports --auto-correct.
-# Configuration parameters: IgnoredMethods.
-# IgnoredMethods: respond_to, define_method
-Style/SymbolProc:
-  Exclude:
-    - 'app/controllers/activities_controller.rb'
-    - 'app/models/activity.rb'
-    - 'app/models/member.rb'
-    - 'db/migrate/20180904163645_generate_calendar_tokens.rb'
-
 # Offense count: 3
 # Cop supports --auto-correct.
 # Configuration parameters: WordRegex.

app/controllers/activities_controller.rb

     uploaded_io = params[:spreadsheet]
     result = Activity.from_csv(uploaded_io.read, @group)
 
-    result.each do |a|
-      a.save!
-    end
+    result.each(&:save!)
 
     flash_message(:success, I18n.t('activities.mass_imported', count: result.count))
     redirect_to group_activities_path(@group)

app/helpers/authentication_helper.rb

 
       return false if !@user_session.active || @user_session.expires < Time.now
 
-      return true
+      true
 
     else
       # Case 2: User is returning and has a remember token saved.
         return false
       end
 
-      return false
+      false
     end
   end
 
     Raven.user_context(
       user_firstname: current_person.first_name
     )
-    return true
+    true
   end
 
   def require_admin!

app/models/activity.rb

     p = c[true]
     a = c[false]
     u = c[nil]
-    return "#{p || 0}, #{a || 0}, #{u || 0}"
+    "#{p || 0}, #{a || 0}, #{u || 0}"
   end
 
   # Determine whether the passed Person may change this activity.
     return if self.reminder_at > Time.zone.now
 
     participants = self.participants.where(attending: nil)
-    participants.each { |p| p.send_reminder }
+    participants.each(&:send_reminder)
 
     self.reminder_done = true
     self.save
          .joins(:person)
          .where.not(subgroup: nil)
 
-    ps.each do |pp|
-      pp.send_subgroup_notification
-    end
+    ps.each(&:send_subgroup_notification)
   end
 
   private

app/models/member.rb

       activity: self.group.future_activities
     )
 
-    participants.each do |p|
-      p.destroy!
-    end
+    participants.each(&:destroy!)
   end
 end

app/models/person.rb

       result << p
     end
 
-    return result
+    result
   end
 
   # @return [String]

db/migrate/20180904163645_generate_calendar_tokens.rb

 class GenerateCalendarTokens < ActiveRecord::Migration[5.0]
   def up
-    Person.all.each do |p|
-      p.regenerate_calendar_token
-    end
+    Person.all.each(&:regenerate_calendar_token)
   end
 
   def down; end