schema_up_to_date?

# File activerecord/lib/active_record/tasks/database_tasks.rb, line 383
      def schema_up_to_date?(configuration, format = ActiveRecord.schema_format, file = nil)
        db_config = resolve_configuration(configuration)

        file ||= schema_dump_path(db_config)

        return true unless File.exist?(file)

        ActiveRecord::Base.establish_connection(db_config)

        return false unless ActiveRecord::InternalMetadata.enabled?
        return false unless ActiveRecord::InternalMetadata.table_exists?

        ActiveRecord::InternalMetadata[:schema_sha1] == schema_sha1(file)
      end