Inherit from ApplicationRecord instead of ActiveRecord::Base

app/models/clusters/group.rb

 # frozen_string_literal: true
 module Clusters
-  class Group < ActiveRecord::Base
+  class Group < ApplicationRecord
     self.table_name = 'cluster_groups'
     belongs_to :cluster, class_name: 'Clusters::Cluster'

app/models/clusters/kubernetes_namespace.rb

 # frozen_string_literal: true
 module Clusters
-  class KubernetesNamespace < ActiveRecord::Base
+  class KubernetesNamespace < ApplicationRecord
     include Gitlab::Kubernetes
     self.table_name = 'clusters_kubernetes_namespaces'

app/models/clusters/platforms/kubernetes.rb

@@ -2,7 +2,7 @@
 module Clusters
   module Platforms
-    class Kubernetes < ActiveRecord::Base
+    class Kubernetes < ApplicationRecord
       include Gitlab::Kubernetes
       include ReactiveCaching
       include EnumWithNil

app/models/clusters/project.rb

 # frozen_string_literal: true
 module Clusters
-  class Project < ActiveRecord::Base
+  class Project < ApplicationRecord
     self.table_name = 'cluster_projects'
     belongs_to :cluster, class_name: 'Clusters::Cluster'

app/models/clusters/providers/gcp.rb

@@ -2,7 +2,7 @@
 module Clusters
   module Providers
-    class Gcp < ActiveRecord::Base
+    class Gcp < ApplicationRecord
       self.table_name = 'cluster_providers_gcp'
       belongs_to :cluster, inverse_of: :provider_gcp, class_name: 'Clusters::Cluster'

app/models/commit_status.rb

 # frozen_string_literal: true
-class CommitStatus < ActiveRecord::Base
+class CommitStatus < ApplicationRecord
   include HasStatus
   include Importable
   include AfterCommitQueue

app/models/concerns/atomic_internal_id.rb

@@ -7,7 +7,7 @@
 #
 # For example, let's generate internal ids for Issue per Project:
 # ```
-# class Issue < ActiveRecord::Base
+# class Issue < ApplicationRecord
 #   has_internal_id :iid, scope: :project, init: ->(s) { s.project.issues.maximum(:iid) }
 # end
 # ```

app/models/concerns/ignorable_column.rb

@@ -5,7 +5,7 @@
 #
 # Example:
 #
-#     class User < ActiveRecord::Base
+#     class User < ApplicationRecord
 #       include IgnorableColumn
 #
 #       ignore_column :updated_at

app/models/concerns/participable.rb

@@ -7,7 +7,7 @@
 #
 # Usage:
 #
-#     class Issue < ActiveRecord::Base
+#     class Issue < ApplicationRecord
 #       include Participable
 #
 #       # ...

app/models/concerns/reactive_caching.rb

@@ -7,7 +7,7 @@
 #
 # Example of use:
 #
-#    class Foo < ActiveRecord::Base
+#    class Foo < ApplicationRecord
 #      include ReactiveCaching
 #
 #      self.reactive_cache_key = ->(thing) { ["foo", thing.id] }

app/models/concerns/sha_attribute.rb

@@ -39,7 +39,7 @@ module ShaAttribute
     end
     def database_exists?
-      ActiveRecord::Base.connection
+      ApplicationRecord.connection
       true
     rescue

app/models/concerns/strip_attribute.rb

@@ -6,7 +6,7 @@
 #
 # Usage:
 #
-#     class Milestone < ActiveRecord::Base
+#     class Milestone < ApplicationRecord
 #       strip_attributes :title
 #     end
 #

app/models/container_repository.rb

 # frozen_string_literal: true
-class ContainerRepository < ActiveRecord::Base
+class ContainerRepository < ApplicationRecord
   include Gitlab::Utils::StrongMemoize
   belongs_to :project

app/models/conversational_development_index/metric.rb

 # frozen_string_literal: true
 module ConversationalDevelopmentIndex
-  class Metric < ActiveRecord::Base
+  class Metric < ApplicationRecord
     include Presentable
     self.table_name = 'conversational_development_index_metrics'

app/models/deploy_keys_project.rb

 # frozen_string_literal: true
-class DeployKeysProject < ActiveRecord::Base
+class DeployKeysProject < ApplicationRecord
   belongs_to :project
   belongs_to :deploy_key, inverse_of: :deploy_keys_projects

app/models/deploy_token.rb

 # frozen_string_literal: true
-class DeployToken < ActiveRecord::Base
+class DeployToken < ApplicationRecord
   include Expirable
   include TokenAuthenticatable
   include PolicyActor

app/models/deployment.rb

 # frozen_string_literal: true
-class Deployment < ActiveRecord::Base
+class Deployment < ApplicationRecord
   include AtomicInternalId
   include IidRoutes
   include AfterCommitQueue

app/models/email.rb

 # frozen_string_literal: true
-class Email < ActiveRecord::Base
+class Email < ApplicationRecord
   include Sortable
   include Gitlab::SQL::Pattern

app/models/environment.rb

 # frozen_string_literal: true
-class Environment < ActiveRecord::Base
+class Environment < ApplicationRecord
   include Gitlab::Utils::StrongMemoize
   # Used to generate random suffixes for the slug
   LETTERS = 'a'..'z'

app/models/epic.rb

@@ -2,7 +2,7 @@
 # Placeholder class for model that is implemented in EE
 # It reserves '&' as a reference prefix, but the table does not exists in CE
-class Epic < ActiveRecord::Base
+class Epic < ApplicationRecord
   def self.link_reference_pattern
     nil
   end