Rails/ReversibleMigrationMethodDefinition false positive when up and down defined as class methods

[marcoroth]

Expected behavior

A migration like this shouldn't add a Rails/ReversibleMigrationMethodDefinition offense:

class SomeMigration < ActiveRecord::Migration[7.1]
  def self.up
    # ...
  end

  def self.down
    # ...
  end
end

Actual behavior

It's adding the following offense:

# db/migrate/some_migration.rb:1:1: C: Rails/ReversibleMigrationMethodDefinition: Migrations must contain either a change method, or both an up and a down method.

# class SomeMigration < ActiveRecord::Migration[7.1] ...
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Steps to reproduce the problem

1. Create file db/migrate/some_migration.rb
2. Copy the file content from above
3. Run RuboCop with rubocop-rails required and the Rails/ReversibleMigrationMethodDefinition cop enabled

Rails/ReversibleMigrationMethodDefinition:
  Enabled: true

RuboCop version

❯ bundle exec rubocop -V
1.60.1 (using Parser 3.3.0.5, rubocop-ast 1.30.0, running on ruby 3.3.0) [x86_64-darwin23]
  - rubocop-rails 2.23.1

[Earlopain]

This working seems like an implementation detail, I don't find any documentation on this.

Trying to do the same with change doesn't work at all.