1 files changed, 54 insertions, 0 deletions
diff --git a/rubocop/cop/migration/schedule_async.rb b/rubocop/cop/migration/schedule_async.rb
new file mode 100644
index 00000000000..f296628c3d6
--- /dev/null
+++ b/rubocop/cop/migration/schedule_async.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require_relative '../../migration_helpers'
+
+module RuboCop
+  module Cop
+    module Migration
+      class ScheduleAsync < RuboCop::Cop::Cop
+        include MigrationHelpers
+
+        ENFORCED_SINCE = 2020_02_12_00_00_00
+
+        MSG = <<~MSG
+          Don't call the background migration worker directly, use the `#migrate_async`,
+          `#migrate_in`, `#bulk_migrate_async` or `#bulk_migrate_in` migration helpers
+          instead.
+        MSG
+
+        def_node_matcher :calls_background_migration_worker?, <<~PATTERN
+          (send (const nil? :BackgroundMigrationWorker) {:perform_async :perform_in :bulk_perform_async :bulk_perform_in} ... )
+        PATTERN
+
+        def on_send(node)
+          return unless in_migration?(node)
+          return if version(node) < ENFORCED_SINCE
+
+          add_offense(node, location: :expression) if calls_background_migration_worker?(node)
+        end
+
+        def autocorrect(node)
+          # This gets rid of the receiver `BackgroundMigrationWorker` and
+          # replaces `perform` with `schedule`
+          schedule_method = method_name(node).to_s.sub('perform', 'migrate')
+          arguments = arguments(node).map(&:source).join(', ')
+
+          replacement = "#{schedule_method}(#{arguments})"
+          lambda do |corrector|
+            corrector.replace(node.source_range, replacement)
+          end
+        end
+
+        private
+
+        def method_name(node)
+          node.children.second
+        end
+
+        def arguments(node)
+          node.children[2..-1]
+        end
+      end
+    end
+  end
+end