diff --git a/db/structure.sql b/db/structure.sql
index 3fd5e4bca..e6c9c147d 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -7380,6 +7380,14 @@ CREATE INDEX proof_of_identity_type_id_and_proof_of_identity_refusal_id ON publi
 CREATE UNIQUE INDEX unique_not_null_external_id ON public.invoicing_profiles USING btree (external_id) WHERE (external_id IS NOT NULL);
 
 
+--
+-- Name: accounting_periods accounting_periods_del_protect; Type: RULE; Schema: public; Owner: -
+--
+
+CREATE RULE accounting_periods_del_protect AS
+    ON DELETE TO public.accounting_periods DO INSTEAD NOTHING;
+
+
 --
 -- Name: accounting_periods accounting_periods_upd_protect; Type: RULE; Schema: public; Owner: -
 --
diff --git a/lib/omni_auth/strategies/sso_oauth2_provider.rb b/lib/omni_auth/strategies/sso_oauth2_provider.rb
index 150f23393..2f4e8892d 100644
--- a/lib/omni_auth/strategies/sso_oauth2_provider.rb
+++ b/lib/omni_auth/strategies/sso_oauth2_provider.rb
@@ -22,7 +22,6 @@ module OmniAuth::Strategies
     # Strategy name.
     option :name, active_provider.strategy_name
 
-
     option :client_options,
            site: active_provider.providable.base_url,
            authorize_url: active_provider.providable.authorization_endpoint,
@@ -39,7 +38,7 @@ module OmniAuth::Strategies
       "#{url[:protocol]}://#{url[:host]}#{script_name}#{callback_path}"
     end
 
-    uid { parsed_info['user.uid'.to_sym] }
+    uid { parsed_info[:'user.uid'] }
 
     info do
       {
diff --git a/lib/pay_zen/pci/charge.rb b/lib/pay_zen/pci/charge.rb
index 5e20573da..22ff07e5c 100644
--- a/lib/pay_zen/pci/charge.rb
+++ b/lib/pay_zen/pci/charge.rb
@@ -32,6 +32,4 @@ class PayZen::PCI::Charge < PayZen::Client
          device: device,
          paymentForms: payment_forms)
   end
-
 end
-
diff --git a/lib/sidekiq/server_locale.rb b/lib/sidekiq/server_locale.rb
index 7add106a4..ec968042a 100644
--- a/lib/sidekiq/server_locale.rb
+++ b/lib/sidekiq/server_locale.rb
@@ -1,12 +1,14 @@
-module FabManager
-  module Middleware
-    class ServerLocale
-      def call(worker_class, job, queue)
-        locale = job['locale'] || Rails.application.secrets.rails_locale
-        I18n.with_locale(locale) do
-          yield
-        end
-      end
+# frozen_string_literal: true
+
+# module definition
+module FabManager::Middleware; end
+
+# Provides localization in workers
+class FabManager::Middleware::ServerLocale
+  def call(_worker_class, job, _queue)
+    locale = job['locale'] || Rails.application.secrets.rails_locale
+    I18n.with_locale(locale) do
+      yield
     end
   end
-end
\ No newline at end of file
+end
diff --git a/lib/sso_logger.rb b/lib/sso_logger.rb
index ddcf49fc4..333383315 100644
--- a/lib/sso_logger.rb
+++ b/lib/sso_logger.rb
@@ -2,9 +2,9 @@
 
 # This class provides logging functionalities for SSO authentication
 class SsoLogger
-  def initialize()
-    @logger = ActiveSupport::TaggedLogging.new(Logger.new(STDOUT))
-    @log_status = ENV.fetch('SSO_DEBUG') { false }
+  def initialize
+    @logger = ActiveSupport::TaggedLogging.new(Logger.new($stdout))
+    @log_status = ENV.fetch('SSO_DEBUG', false)
   end
 
   def debug(message)
diff --git a/lib/tasks/db.rake b/lib/tasks/db.rake
index ab8be6329..085cb0aa9 100644
--- a/lib/tasks/db.rake
+++ b/lib/tasks/db.rake
@@ -3,20 +3,20 @@
 namespace :db do
   desc 'Convert development DB to Rails test fixtures'
   task :to_fixtures, [:table] => :environment do |_task, args|
-    TABLES_TO_SKIP = %w[ar_internal_metadata delayed_jobs schema_info schema_migrations].freeze
+    tables_to_skip = %w[ar_internal_metadata delayed_jobs schema_info schema_migrations].freeze
 
     begin
       ActiveRecord::Base.establish_connection
       ActiveRecord::Base.connection.tables.each do |table_name|
-        next if TABLES_TO_SKIP.include?(table_name)
+        next if tables_to_skip.include?(table_name)
         next if args.table && args.table != table_name
 
         conter = '000'
-        file_path = "#{Rails.root}/test/fixtures/test/#{table_name}.yml"
+        file_path = Rails.root.join("test/fixtures/test/#{table_name}.yml")
         File.open(file_path, 'w') do |file|
           rows = ActiveRecord::Base.connection.select_all("SELECT * FROM #{table_name}")
           data = rows.each_with_object({}) do |record, hash|
-            suffix = record['id'].blank? ? conter.succ! : record['id']
+            suffix = record['id'].presence || conter.succ!
             hash["#{table_name.singularize}_#{suffix}"] = record
           end
           puts "Writing table '#{table_name}' to '#{file_path}'"
diff --git a/lib/tasks/fablab/auth.rake b/lib/tasks/fablab/auth.rake
index 9269a6771..6e4e58ad3 100644
--- a/lib/tasks/fablab/auth.rake
+++ b/lib/tasks/fablab/auth.rake
@@ -3,7 +3,6 @@
 # SSO and authentication relative tasks
 namespace :fablab do
   namespace :auth do
-
     desc 'switch the active authentication provider'
     task :switch_provider, [:provider] => :environment do |_task, args|
       providers = AuthProvider.all.inject('') { |str, item| "#{str}#{item[:name]}, " }
@@ -24,18 +23,18 @@ namespace :fablab do
 
       # disable previous provider
       prev_prev = AuthProvider.previous
-      prev_prev&.update_attribute(:status, 'pending')
+      prev_prev&.update(status: 'pending')
 
-      AuthProvider.active.update_attribute(:status, 'previous') unless AuthProvider.active.name == 'DatabaseProvider::SimpleAuthProvider'
+      AuthProvider.active.update(status: 'previous') unless AuthProvider.active.name == 'DatabaseProvider::SimpleAuthProvider'
 
       # enable given provider
-      AuthProvider.find_by(name: args.provider).update_attribute(:status, 'active')
+      AuthProvider.find_by(name: args.provider).update(status: 'active')
 
       # migrate the current users.
       if AuthProvider.active.providable_type == DatabaseProvider.name
         User.all.each do |user|
           # Concerns local database provider
-          user.update_attribute(:auth_token, nil)
+          user.update(auth_token: nil)
         end
       else
         # Concerns any providers except local database
@@ -54,7 +53,6 @@ namespace :fablab do
 
     desc 'notify users that the auth provider has changed'
     task notify_changed: :environment do
-
       I18n.locale = I18n.default_locale
 
       # notify every users if the provider is not local database provider
diff --git a/lib/tasks/fablab/payzen.rake b/lib/tasks/fablab/payzen.rake
index 89316adb3..92219fa00 100644
--- a/lib/tasks/fablab/payzen.rake
+++ b/lib/tasks/fablab/payzen.rake
@@ -3,7 +3,6 @@
 # PayZen relative tasks
 namespace :fablab do
   namespace :payzen do
-
     # example: rails fablab:payzen:replay_on_payment_success[54a35f3f6fdd729ac72b6da0,53,57,3,247]
     # to find the parameters, search the logs, example:
     # Started POST "/api/payzen/confirm_payment" for 93.27.29.108 at 2022-04-04 20:26:12 +0000
@@ -22,7 +21,7 @@ namespace :fablab do
     # ], "payment_method"=>"card"}, "order_id"=>"704cc55e23f00ac3d238d8de"}}
     desc 'replay PayzenController#on_payment_success for a given event'
     task :replay_on_payment_success, %i[gateway_item_id user_id event_id nb_reserve_places slot_id] => :environment do |_task, args|
-      ActiveRecord::Base.logger = Logger.new STDOUT
+      ActiveRecord::Base.logger = Logger.new $stdout
 
       gateway_item_type = 'PayZen::Order'
 
diff --git a/lib/tasks/fablab/setup.rake b/lib/tasks/fablab/setup.rake
index aac3c23e9..b685a284f 100644
--- a/lib/tasks/fablab/setup.rake
+++ b/lib/tasks/fablab/setup.rake
@@ -20,7 +20,7 @@ namespace :fablab do
           setting_id: setting.id,
           user_id: User.admins.first.id,
           value: 'false',
-          created_at: DateTime.parse(args.date)
+          created_at: Time.zone.parse(args.date)
         )
       else
         setting = Setting.find_by(name: 'invoice_VAT-rate')
@@ -28,7 +28,7 @@ namespace :fablab do
           setting_id: setting.id,
           user_id: User.admins.first.id,
           value: args.rate,
-          created_at: DateTime.parse(args.date)
+          created_at: Time.zone.parse(args.date)
         )
       end
     end
@@ -120,15 +120,15 @@ namespace :fablab do
       Group.find_by(slug: 'admins').destroy
       if Setting.get('user_validation_required')
         print "\e[91m::\e[0m \e[1mValidating the 'admins'...\e[0m\n"
-        User.admins.each { |admin| admin.update(validated_at: DateTime.current) if admin.validated_at.nil? }
+        User.admins.each { |admin| admin.update(validated_at: Time.current) if admin.validated_at.nil? }
       end
       print "\e[32m✅\e[0m \e[1mDone\e[0m\n"
     end
 
     desc 'generate acconting lines'
     task build_accounting_lines: :environment do
-      start_date = Invoice.order(created_at: :asc).first&.created_at || DateTime.current
-      end_date = DateTime.current
+      start_date = Invoice.order(created_at: :asc).first&.created_at || Time.current
+      end_date = Time.current
       AccountingLine.where(date: start_date..end_date).destroy_all
       Accounting::AccountingService.new.build(start_date&.beginning_of_day, end_date.end_of_day)
       puts '-> Done'
diff --git a/lib/tasks/fablab/stripe.rake b/lib/tasks/fablab/stripe.rake
index c8bba5466..b29c32b5c 100644
--- a/lib/tasks/fablab/stripe.rake
+++ b/lib/tasks/fablab/stripe.rake
@@ -3,7 +3,6 @@
 # Stripe relative tasks
 namespace :fablab do
   namespace :stripe do
-
     desc 'find any invoices with incoherent total between stripe and DB'
     task :find_incoherent_invoices, [:start_date] => :environment do |_task, args|
       puts 'DEPRECATION WARNING: Will not work for invoices created from version 4.1.0 and above'
@@ -61,8 +60,9 @@ namespace :fablab do
 
     desc 'set stripe as the default payment gateway'
     task set_gateway: :environment do
-      if Setting.find_by(name: 'stripe_public_key').try(:value) && Setting.find_by(name: 'stripe_secret_key').try(:value)
-        Setting.set('payment_gateway', 'stripe') unless Setting.find_by(name: 'payment_gateway').try(:value)
+      if Setting.find_by(name: 'stripe_public_key').try(:value) && Setting.find_by(name: 'stripe_secret_key').try(:value) &&
+         !Setting.find_by(name: 'payment_gateway').try(:value)
+        Setting.set('payment_gateway', 'stripe')
       end
     end
 
@@ -72,7 +72,7 @@ namespace :fablab do
     task reset_cards: :environment do
       unless Rails.env.test?
         print "You're about to detach all payment cards from all customers. This was only made for test mode. Are you sure? (y/n) "
-        confirm = STDIN.gets.chomp
+        confirm = $stdin.gets.chomp
         next unless confirm == 'y'
       end
       User.all.each do |user|
diff --git a/test/integration/open_api/trainings_test.rb b/test/integration/open_api/trainings_test.rb
index deda96800..9792044f8 100644
--- a/test/integration/open_api/trainings_test.rb
+++ b/test/integration/open_api/trainings_test.rb
@@ -13,5 +13,4 @@ class OpenApi::TrainingsTest < ActionDispatch::IntegrationTest
     get '/open_api/v1/trainings', headers: open_api_headers(@token)
     assert_response :success
   end
-
 end
diff --git a/test/models/event_price_category_test.rb b/test/models/event_price_category_test.rb
index 2b1733689..d845ff549 100644
--- a/test/models/event_price_category_test.rb
+++ b/test/models/event_price_category_test.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class EventPriceCategoryTest < ActiveSupport::TestCase
   test "event price's category cannot be empty" do
-    epc = EventPriceCategory.new({price_category_id: 1, event_id: 3})
+    epc = EventPriceCategory.new({ price_category_id: 1, event_id: 3 })
     assert epc.invalid?
     assert epc.errors[:amount].present?
   end
diff --git a/test/models/event_test.rb b/test/models/event_test.rb
index 63685e4a4..ffd968c91 100644
--- a/test/models/event_test.rb
+++ b/test/models/event_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class EventTest < ActiveSupport::TestCase
diff --git a/test/models/export_test.rb b/test/models/export_test.rb
index f2dd2116b..478282376 100644
--- a/test/models/export_test.rb
+++ b/test/models/export_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ExportTest < ActiveSupport::TestCase
diff --git a/test/models/price_category_test.rb b/test/models/price_category_test.rb
index a41deaf46..52496f6cf 100644
--- a/test/models/price_category_test.rb
+++ b/test/models/price_category_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class PriceCategoryTest < ActiveSupport::TestCase
diff --git a/test/models/ticket_test.rb b/test/models/ticket_test.rb
index 5007c4e81..ba11a82dd 100644
--- a/test/models/ticket_test.rb
+++ b/test/models/ticket_test.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TicketTest < ActiveSupport::TestCase
-  test "ticket must have at least 1 seat" do
-    t = Ticket.new({event_price_category_id: 1, booked: -1})
+  test 'ticket must have at least 1 seat' do
+    t = Ticket.new({ event_price_category_id: 1, booked: -1 })
     assert t.invalid?
     assert t.errors[:booked].present?
   end
diff --git a/test/models/wallet_test.rb b/test/models/wallet_test.rb
index 16dbb76bf..11833f27e 100644
--- a/test/models/wallet_test.rb
+++ b/test/models/wallet_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class WalletTest < ActiveSupport::TestCase
diff --git a/test/models/wallet_transaction_test.rb b/test/models/wallet_transaction_test.rb
index ec79d65ed..2ae7b65d5 100644
--- a/test/models/wallet_transaction_test.rb
+++ b/test/models/wallet_transaction_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class WalletTransactionTest < ActiveSupport::TestCase
diff --git a/test/services/users_credits_manager_test.rb b/test/services/users_credits_manager_test.rb
index 729ac18d2..b4042705a 100644
--- a/test/services/users_credits_manager_test.rb
+++ b/test/services/users_credits_manager_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class UsersCreditsManagerTest < ActiveSupport::TestCase
diff --git a/test/services/users_export_service_test.rb b/test/services/users_export_service_test.rb
index 90d9cf1e0..49c4d01a4 100644
--- a/test/services/users_export_service_test.rb
+++ b/test/services/users_export_service_test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class UsersExportServiceTest < ActiveSupport::TestCase