diff --git a/Gemfile.lock b/Gemfile.lock
index ea8e8f632..9bf7b7ffc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -357,7 +357,7 @@ GEM
       omniauth (~> 1.5)
       omniauth-oauth2 (>= 1.4.0)
     openssl (2.1.2)
-    parallel (1.19.2)
+    parallel (1.20.0)
     parser (2.7.2.0)
       ast (~> 2.4.1)
     pg (0.21.0)
@@ -452,13 +452,13 @@ GEM
       rspec-support (~> 3.9.0)
     rspec-support (3.9.3)
     rszr (0.5.2)
-    rubocop (1.2.0)
+    rubocop (1.3.0)
       parallel (~> 1.10)
       parser (>= 2.7.1.5)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8)
       rexml
-      rubocop-ast (>= 1.0.1)
+      rubocop-ast (>= 1.1.1)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 2.0)
     rubocop-ast (1.1.1)
@@ -533,7 +533,7 @@ GEM
       faraday (~> 0.9)
       jwt (>= 1.5, <= 2.5)
       nokogiri (>= 1.6, < 2.0)
-    tzinfo (1.2.7)
+    tzinfo (1.2.8)
       thread_safe (~> 0.1)
     uglifier (4.1.20)
       execjs (>= 0.3.0, < 3)
diff --git a/app/controllers/application_controller/handles_errors.rb b/app/controllers/application_controller/handles_errors.rb
index 65e213194..fd558bdc7 100644
--- a/app/controllers/application_controller/handles_errors.rb
+++ b/app/controllers/application_controller/handles_errors.rb
@@ -77,9 +77,7 @@ module ApplicationController::HandlesErrors
       data[:error_human] = $1
     elsif e.message.match?(/(already exists|duplicate key|duplicate entry)/i)
       data[:error_human] = 'Object already exists!'
-    elsif e.message =~ /null value in column "(.+?)" violates not-null constraint/i
-      data[:error_human] = "Attribute '#{$1}' required!"
-    elsif e.message =~ /Field '(.+?)' doesn't have a default value/i
+    elsif e.message =~ /null value in column "(.+?)" violates not-null constraint/i || e.message =~ /Field '(.+?)' doesn't have a default value/i
       data[:error_human] = "Attribute '#{$1}' required!"
     elsif e.message == 'Exceptions::NotAuthorized'
       data[:error]       = 'Not authorized'
diff --git a/app/controllers/first_steps_controller.rb b/app/controllers/first_steps_controller.rb
index ede641098..fe5f91120 100644
--- a/app/controllers/first_steps_controller.rb
+++ b/app/controllers/first_steps_controller.rb
@@ -220,21 +220,7 @@ class FirstStepsController < ApplicationController
   end
 
   def check_availability(result)
-    test_ticket_active = true
-    overview = test_overview
-
-    if !overview
-      test_ticket_active = false
-    elsif overview.updated_by_id != 1
-      test_ticket_active = false
-    end
-    if !test_customer
-      test_ticket_active = false
-    end
-    if Group.where(active: true, name: 'Users').count.zero?
-      test_ticket_active = false
-    end
-    return result if test_ticket_active
+    return result if test_ticket_active?
 
     result.each do |item|
       items = []
@@ -248,4 +234,14 @@ class FirstStepsController < ApplicationController
     result
   end
 
+  def test_ticket_active?
+    overview = test_overview
+
+    return false if !overview
+    return false if overview.updated_by_id != 1
+    return false if !test_customer
+    return false if Group.where(active: true, name: 'Users').count.zero?
+
+    true
+  end
 end
diff --git a/app/models/channel/driver.rb b/app/models/channel/driver.rb
index fe4f9321e..55f2cbe6e 100644
--- a/app/models/channel/driver.rb
+++ b/app/models/channel/driver.rb
@@ -1,4 +1,4 @@
 class Channel
-  class Driver
+  class Driver # rubocop:disable Lint/EmptyClass
   end
 end
diff --git a/app/models/channel/email_parser.rb b/app/models/channel/email_parser.rb
index acfc93623..5616b088e 100644
--- a/app/models/channel/email_parser.rb
+++ b/app/models/channel/email_parser.rb
@@ -700,11 +700,7 @@ process unprocessable_mails (tmp/unprocessable_mail/*.eml) again
     rescue
       begin
         case file.header[:content_disposition].to_s
-        when /(filename|name)(\*{0,1})="(.+?)"/i
-          filename = $3
-        when /(filename|name)(\*{0,1})='(.+?)'/i
-          filename = $3
-        when /(filename|name)(\*{0,1})=(.+?);/i
+        when /(filename|name)(\*{0,1})="(.+?)"/i, /(filename|name)(\*{0,1})='(.+?)'/i, /(filename|name)(\*{0,1})=(.+?);/i
           filename = $3
         end
       rescue
@@ -714,11 +710,7 @@ process unprocessable_mails (tmp/unprocessable_mail/*.eml) again
 
     begin
       case file.header[:content_disposition].to_s
-      when /(filename|name)(\*{0,1})="(.+?)"/i
-        filename = $3
-      when /(filename|name)(\*{0,1})='(.+?)'/i
-        filename = $3
-      when /(filename|name)(\*{0,1})=(.+?);/i
+      when /(filename|name)(\*{0,1})="(.+?)"/i, /(filename|name)(\*{0,1})='(.+?)'/i, /(filename|name)(\*{0,1})=(.+?);/i
         filename = $3
       end
     rescue
@@ -728,11 +720,7 @@ process unprocessable_mails (tmp/unprocessable_mail/*.eml) again
     # as fallback, use raw values
     if filename.blank?
       case headers_store['Content-Disposition'].to_s
-      when /(filename|name)(\*{0,1})="(.+?)"/i
-        filename = $3
-      when /(filename|name)(\*{0,1})='(.+?)'/i
-        filename = $3
-      when /(filename|name)(\*{0,1})=(.+?);/i
+      when /(filename|name)(\*{0,1})="(.+?)"/i, /(filename|name)(\*{0,1})='(.+?)'/i, /(filename|name)(\*{0,1})=(.+?);/i
         filename = $3
       end
     end
diff --git a/app/models/channel/filter/monitoring_base.rb b/app/models/channel/filter/monitoring_base.rb
index 20be1d1cf..cc3ec66cc 100644
--- a/app/models/channel/filter/monitoring_base.rb
+++ b/app/models/channel/filter/monitoring_base.rb
@@ -66,9 +66,7 @@ class Channel::Filter::MonitoringBase
     # possible event types https://mmonit.com/monit/documentation/#Setting-an-event-filter
     if result['state'].blank?
       result['state'] = case mail[:body]
-                        when /\s(done|recovery|succeeded|bytes\sok|packets\sok)\s/
-                          'OK'
-                        when /(instance\schanged\snot|Link\sup|Exists|Saturation\sok|Speed\sok)/
+                        when /\s(done|recovery|succeeded|bytes\sok|packets\sok)\s/, /(instance\schanged\snot|Link\sup|Exists|Saturation\sok|Speed\sok)/
                           'OK'
                         else
                           'CRITICAL'
diff --git a/app/models/cti/log.rb b/app/models/cti/log.rb
index 14cfa51d7..d537550da 100644
--- a/app/models/cti/log.rb
+++ b/app/models/cti/log.rb
@@ -426,9 +426,7 @@ Cti::Log.process(
         log.with_lock do
           log.done = done
           if params['direction'] == 'in'
-            if log.state == 'newCall' && cause != 'forwarded'
-              log.done = false
-            elsif log.to_comment == 'voicemail'
+            if (log.state == 'newCall' && cause != 'forwarded') || log.to_comment == 'voicemail' # rubocop:disable Style/SoleNestedConditional
               log.done = false
             end
           end
diff --git a/app/models/object_manager/attribute.rb b/app/models/object_manager/attribute.rb
index 315af7aa4..962796ca1 100644
--- a/app/models/object_manager/attribute.rb
+++ b/app/models/object_manager/attribute.rb
@@ -591,15 +591,7 @@ to send no browser reload event, pass false
             limit: attribute.data_option[:maxlength],
             null:  true
           )
-        when /^integer|user_autocompletion|datetime|date$/
-          ActiveRecord::Migration.change_column(
-            model.table_name,
-            attribute.name,
-            data_type,
-            default: attribute.data_option[:default],
-            null:    true
-          )
-        when /^boolean|active$/
+        when /^integer|user_autocompletion|datetime|date$/, /^boolean|active$/
           ActiveRecord::Migration.change_column(
             model.table_name,
             attribute.name,
@@ -631,23 +623,7 @@ to send no browser reload event, pass false
           limit: attribute.data_option[:maxlength],
           null:  true
         )
-      when /^integer|user_autocompletion$/
-        ActiveRecord::Migration.add_column(
-          model.table_name,
-          attribute.name,
-          data_type,
-          default: attribute.data_option[:default],
-          null:    true
-        )
-      when /^boolean|active$/
-        ActiveRecord::Migration.add_column(
-          model.table_name,
-          attribute.name,
-          data_type,
-          default: attribute.data_option[:default],
-          null:    true
-        )
-      when /^datetime|date$/
+      when /^integer|user_autocompletion$/, /^boolean|active$/, /^datetime|date$/
         ActiveRecord::Migration.add_column(
           model.table_name,
           attribute.name,
diff --git a/app/models/ticket/escalation.rb b/app/models/ticket/escalation.rb
index c52ce7031..681993e67 100644
--- a/app/models/ticket/escalation.rb
+++ b/app/models/ticket/escalation.rb
@@ -98,6 +98,7 @@ returns
     end
 
     # get last_update_at
+    # rubocop:disable Lint/DuplicateBranch
     if !last_contact_customer_at && !last_contact_agent_at
       last_update_at = created_at
     elsif !last_contact_customer_at && last_contact_agent_at
@@ -109,6 +110,7 @@ returns
     elsif last_contact_agent_at < last_contact_customer_at
       last_update_at = last_contact_customer_at
     end
+    # rubocop:enable Lint/DuplicateBranch
 
     # check if calculation need be done
     escalation_calculation = preferences[:escalation_calculation] || {}
diff --git a/app/models/transaction/notification.rb b/app/models/transaction/notification.rb
index 672db04c6..4b4a813cb 100644
--- a/app/models/transaction/notification.rb
+++ b/app/models/transaction/notification.rb
@@ -245,11 +245,8 @@ class Transaction::Notification
     @item[:changes].each do |key, value|
 
       # if no config exists, use all attributes
-      if attribute_list.blank?
-        user_related_changes[key] = value
-
-      # if config exists, just use existing attributes for user
-      elsif attribute_list[key.to_s]
+      # or if config exists, just use existing attributes for user
+      if attribute_list.blank? || attribute_list[key.to_s]
         user_related_changes[key] = value
       end
     end
diff --git a/app/models/transaction/slack.rb b/app/models/transaction/slack.rb
index 072d0da41..9225247a1 100644
--- a/app/models/transaction/slack.rb
+++ b/app/models/transaction/slack.rb
@@ -214,11 +214,8 @@ class Transaction::Slack
     @item[:changes].each do |key, value|
 
       # if no config exists, use all attributes
-      if attribute_list.blank?
-        user_related_changes[key] = value
-
-      # if config exists, just use existing attributes for user
-      elsif attribute_list[key.to_s]
+      # or if config exists, just use existing attributes for user
+      if attribute_list.blank? || attribute_list[key.to_s]
         user_related_changes[key] = value
       end
     end
diff --git a/lib/core_ext/string.rb b/lib/core_ext/string.rb
index b66bab2ba..f8f9d6a6e 100644
--- a/lib/core_ext/string.rb
+++ b/lib/core_ext/string.rb
@@ -147,9 +147,7 @@ class String
 
         if link_compare.present? && text_compare.blank?
           link
-        elsif link_compare.blank? && text_compare.present?
-          text
-        elsif link_compare && link_compare =~ /^mailto/i
+        elsif (link_compare.blank? && text_compare.present?) || (link_compare && link_compare =~ /^mailto/i)
           text
         elsif link_compare.present? && text_compare.present? && (link_compare == text_compare || link_compare == "mailto:#{text}".downcase || link_compare == "http://#{text}".downcase)
           "######LINKEXT:#{link}/TEXT:#{text}######"
diff --git a/lib/email_address_validation.rb b/lib/email_address_validation.rb
index a9d6f8960..0980f8590 100644
--- a/lib/email_address_validation.rb
+++ b/lib/email_address_validation.rb
@@ -19,7 +19,7 @@ class EmailAddressValidation
   # @return [true]  if email address has valid format
   # @return [false] if email address has no valid format
   def valid_format?
-    # Note: Don't use ValidEmail2::Address.valid? here because it requires the
+    # NOTE: Don't use ValidEmail2::Address.valid? here because it requires the
     # email address to have a dot in its domain.
     @valid_format ||= email_address.match?(URI::MailTo::EMAIL_REGEXP)
   end
diff --git a/lib/excel_sheet.rb b/lib/excel_sheet.rb
index 6a0fd54ec..8fe50c831 100644
--- a/lib/excel_sheet.rb
+++ b/lib/excel_sheet.rb
@@ -74,9 +74,7 @@ class ExcelSheet
     @current_column = 0
     record.each do |item|
       begin
-        if item.acts_like?(:time)
-          value_convert(item, nil, { data_type: 'datetime' })
-        elsif item.acts_like?(:date)
+        if item.acts_like?(:time) || item.acts_like?(:date)
           value_convert(item, nil, { data_type: 'datetime' })
         elsif item.is_a?(Integer) || item.is_a?(Float)
           value_convert(item, nil, { data_type: 'integer' })
diff --git a/lib/facebook.rb b/lib/facebook.rb
index 8fb2dbab4..794072270 100644
--- a/lib/facebook.rb
+++ b/lib/facebook.rb
@@ -137,19 +137,6 @@ result
     }
     if auth
       user = User.find(auth.user_id)
-      map = {
-        #note: 'description',
-      }
-
-      # ignore if value is already set
-      map.each do |target, source|
-        next if user[target].present?
-
-        new_value = tweet_user.send(source).to_s
-        next if new_value.blank?
-
-        user_data[target] = new_value
-      end
       user.update!(user_data)
     else
       user_data[:login] = item_user['id']
diff --git a/lib/import/otrs/helper.rb b/lib/import/otrs/helper.rb
index 687ba770e..52a7cb04f 100644
--- a/lib/import/otrs/helper.rb
+++ b/lib/import/otrs/helper.rb
@@ -20,13 +20,7 @@ module Import
 
       def active?(record)
         case record['ValidID'].to_s
-        when '3'
-          false
-        when '2'
-          false
-        when '1'
-          true
-        when '0'
+        when '3', '2', '0'
           false
         else
           true
diff --git a/lib/notification_factory/mailer.rb b/lib/notification_factory/mailer.rb
index 1e9cdad02..1d6787265 100644
--- a/lib/notification_factory/mailer.rb
+++ b/lib/notification_factory/mailer.rb
@@ -74,9 +74,7 @@ returns
       selected_group_ids = user_preferences['notification_config']['group_ids']
       if selected_group_ids.is_a?(Array)
         hit = nil
-        if selected_group_ids.blank?
-          hit = true
-        elsif selected_group_ids[0] == '-' && selected_group_ids.count == 1
+        if selected_group_ids.blank? || (selected_group_ids[0] == '-' && selected_group_ids.count == 1)
           hit = true
         else
           hit = false
diff --git a/lib/report/article_by_type_sender.rb b/lib/report/article_by_type_sender.rb
index 0d2afca23..2ff319a7b 100644
--- a/lib/report/article_by_type_sender.rb
+++ b/lib/report/article_by_type_sender.rb
@@ -44,9 +44,7 @@ returns
       case params[:interval]
       when 'month'
         params[:range_end] = params[:range_start].next_month
-      when 'week'
-        params[:range_end] = params[:range_start].next_day
-      when 'day'
+      when 'week', 'day'
         params[:range_end] = params[:range_start].next_day
       when 'hour'
         params[:range_end] = params[:range_start] + 1.hour
diff --git a/lib/report/ticket_first_solution.rb b/lib/report/ticket_first_solution.rb
index f26fa6a2d..ea45f548a 100644
--- a/lib/report/ticket_first_solution.rb
+++ b/lib/report/ticket_first_solution.rb
@@ -35,9 +35,7 @@ returns
       case params[:interval]
       when 'month'
         params[:range_end] = params[:range_start].next_month
-      when 'week'
-        params[:range_end] = params[:range_start].next_day
-      when 'day'
+      when 'week', 'day'
         params[:range_end] = params[:range_start].next_day
       when 'hour'
         params[:range_end] = params[:range_start] + 1.hour
diff --git a/lib/report/ticket_generic_time.rb b/lib/report/ticket_generic_time.rb
index 8aa208321..e508f00a8 100644
--- a/lib/report/ticket_generic_time.rb
+++ b/lib/report/ticket_generic_time.rb
@@ -96,9 +96,7 @@ returns
         case params[:interval]
         when 'month'
           params[:range_start] = params[:range_start].next_month
-        when 'week'
-          params[:range_start] = params[:range_start].next_day
-        when 'day'
+        when 'week', 'day'
           params[:range_start] = params[:range_start].next_day
         when 'hour'
           params[:range_start] = params[:range_start] + 1.hour
diff --git a/lib/report/ticket_moved.rb b/lib/report/ticket_moved.rb
index 4494b25ff..c6dcf5e75 100644
--- a/lib/report/ticket_moved.rb
+++ b/lib/report/ticket_moved.rb
@@ -43,9 +43,7 @@ returns
       case params[:interval]
       when 'month'
         params[:range_end] = params[:range_start].next_month
-      when 'week'
-        params[:range_end] = params[:range_start].next_day
-      when 'day'
+      when 'week', 'day'
         params[:range_end] = params[:range_start].next_day
       when 'hour'
         params[:range_end] = params[:range_start] + 1.hour
diff --git a/lib/report/ticket_reopened.rb b/lib/report/ticket_reopened.rb
index ff38c55e2..5d3a781ba 100644
--- a/lib/report/ticket_reopened.rb
+++ b/lib/report/ticket_reopened.rb
@@ -37,9 +37,7 @@ returns
       case params[:interval]
       when 'month'
         params[:range_end] = params[:range_start].next_month
-      when 'week'
-        params[:range_end] = params[:range_start].next_day
-      when 'day'
+      when 'week', 'day'
         params[:range_end] = params[:range_start].next_day
       when 'hour'
         params[:range_end] = params[:range_start] + 1.hour
diff --git a/lib/secure_mailing/backend.rb b/lib/secure_mailing/backend.rb
index f09c96143..7a5b3c17c 100644
--- a/lib/secure_mailing/backend.rb
+++ b/lib/secure_mailing/backend.rb
@@ -1,2 +1,2 @@
-class SecureMailing::Backend
+class SecureMailing::Backend # rubocop:disable Lint/EmptyClass
 end
diff --git a/lib/tasks/search_index_es.rake b/lib/tasks/search_index_es.rake
index ef722b7ab..9c56fd4e1 100644
--- a/lib/tasks/search_index_es.rake
+++ b/lib/tasks/search_index_es.rake
@@ -250,7 +250,7 @@ def get_mapping_properties_object(object)
       result[name][:properties][key] = {
         type: 'integer',
       }
-    elsif value.type == :datetime
+    elsif value.type == :datetime || value.type == :date
       result[name][:properties][key] = {
         type: 'date',
       }
@@ -273,10 +273,6 @@ def get_mapping_properties_object(object)
       result[name][:properties][key] = {
         type: 'float',
       }
-    elsif value.type == :date
-      result[name][:properties][key] = {
-        type: 'date',
-      }
     end
   end
 
diff --git a/lib/telegram.rb b/lib/telegram.rb
index 04fa6f971..7f9646af1 100644
--- a/lib/telegram.rb
+++ b/lib/telegram.rb
@@ -605,7 +605,7 @@ returns
     if params[:channel_post]
       return if params[:channel_post][:new_chat_title] # happens when channel title is renamed, we use [:chat][:title] already, safely ignore this.
 
-      # note: used .blank? which is a rails method. empty? does not work on integers (values like date, width, height)  to check.
+      # NOTE: used .blank? which is a rails method. empty? does not work on integers (values like date, width, height)  to check.
       # need delete_if to remove any empty hashes, .compact only removes keys with nil values.
       params[:message] = {
         document:   {
diff --git a/lib/user_agent.rb b/lib/user_agent.rb
index 5a7c09181..b2479fc5b 100644
--- a/lib/user_agent.rb
+++ b/lib/user_agent.rb
@@ -472,19 +472,7 @@ returns
 
       url = response['location']
       return get(url, params, options, count - 1)
-    when Net::HTTPOK
-      data = nil
-      if options[:json] && !options[:jsonParseDisable] && response.body
-        data = JSON.parse(response.body)
-      end
-      return Result.new(
-        data:         data,
-        body:         response.body,
-        content_type: response['Content-Type'],
-        success:      true,
-        code:         response.code,
-      )
-    when Net::HTTPCreated
+    when Net::HTTPOK, Net::HTTPCreated
       data = nil
       if options[:json] && !options[:jsonParseDisable] && response.body
         data = JSON.parse(response.body)
diff --git a/test/browser/agent_ticket_online_notification_test.rb b/test/browser/agent_ticket_online_notification_test.rb
index 1bcfbfacc..63ab52659 100644
--- a/test/browser/agent_ticket_online_notification_test.rb
+++ b/test/browser/agent_ticket_online_notification_test.rb
@@ -200,7 +200,7 @@ class AgentTicketOnlineNotificationTest < TestCase
     items = browser2.find_elements(css: '.js-notificationsContainer .js-item.is-inactive')
     assert_equal(3, items.count)
 
-    # Note: title update will generate extra notification - so we will have 5
+    # NOTE: title update will generate extra notification - so we will have 5
     ticket_update(
       data: {
         title: 'online notification #5/5',