class method self.check_pending!

# File activerecord/lib/active_record/migration.rb, line 682
      def check_pending!(connection = ActiveRecord::Tasks::DatabaseTasks.migration_connection)
        ActiveRecord.deprecator.warn(<<-MSG.squish)
          The `check_pending!` method is deprecated in favor of `check_all_pending!`. The
          new implementation will loop through all available database configurations and find
          pending migrations. The prior implementation did not permit this.
        MSG

        pending_migrations = connection.migration_context.open.pending_migrations

        if pending_migrations.any?
          raise ActiveRecord::PendingMigrationError.new(pending_migrations: pending_migrations)
        end
      end