1 files changed, 41 insertions, 0 deletions
diff --git a/rubocop/cop/migration/background_migration_record.rb b/rubocop/cop/migration/background_migration_record.rb
new file mode 100644
index 00000000000..2ee6b9f7b42
--- /dev/null
+++ b/rubocop/cop/migration/background_migration_record.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require_relative '../../migration_helpers'
+
+module RuboCop
+  module Cop
+    module Migration
+      class BackgroundMigrationRecord < RuboCop::Cop::Cop
+        include MigrationHelpers
+
+        MSG = <<~MSG
+          Don't use or inherit from ActiveRecord::Base.
+          Use ::ApplicationRecord or ::Ci::ApplicationRecord to ensure the correct database is used.
+          See https://docs.gitlab.com/ee/development/database/batched_background_migrations.html#accessing-data-for-multiple-databases.
+        MSG
+
+        def_node_matcher :inherits_from_active_record_base?, <<~PATTERN
+          (class _ (const (const _ :ActiveRecord) :Base) _)
+        PATTERN
+
+        def_node_search :class_new_active_record_base?, <<~PATTERN
+          (send (const _ :Class) :new (const (const _ :ActiveRecord) :Base) ...)
+        PATTERN
+
+        def on_class(node)
+          return unless in_background_migration?(node)
+          return unless inherits_from_active_record_base?(node)
+
+          add_offense(node, location: :expression)
+        end
+
+        def on_send(node)
+          return unless in_background_migration?(node)
+          return unless class_new_active_record_base?(node)
+
+          add_offense(node, location: :expression)
+        end
+      end
+    end
+  end
+end