Danger requires `frozen_string_literal: true` for [new `.rb` files](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/danger/frozen_string/Dangerfile) https://gitlab.com/gitlab-org/gitlab-ce/issues/47424 added the magic comment for all application files. The next major offender is spec files. Since we move spec files often, we should add this magic comment to all existing spec `.rb` files too. Use this `sed` script which could be useful to replace: ```sh git grep -L frozen_string_literal <directory> | grep "\.rb$" | xargs -n1 sed -i "" '1s/^/# frozen_string_literal: true\'$'\n\\'$'\n/' ```