Follow up to: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/233605#note_3311178345 ### Background > The event is published from here: `app/services/merge_requests/update_service.rb` only, right? So we need to update it only on the Publisher. Subscribers who don't care about the new attribute don't need to be updated. It should be all of them. It should be something like https://docs.gitlab.com/development/event_store/#add-properties, but probably two steps. In this MR add the new property as optional. Then 1 or 2 milestones later just make it non-optional `required`. As part of the work to [implement the `merge_request_ready` flow trigger](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/233605), we updated `MergeRequests::DraftStateChangeEvent` to accept an optional `new_draft_status` property. This allowed the event to be reused for both directions of the draft state transition (draft -> ready and ready -> draft), with subscribers filtering via the conditional `if: ->(event) { event.data[:new_draft_status] == false }`. The property was introduced as optional to keep the rollout backward compatible. #### Goal As per [the docs](https://docs.gitlab.com/development/event_store/#add-properties), schema changes that introduce new required fields must follow a multi-step process to safely handle existing events. This issue covers the second step: 1. ~~[Add](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/233605/diffs?file=b89bcd208d2fac1fac602d34918574069c3e4b38#b89bcd208d2fac1fac602d34918574069c3e4b38_15_15) `new_draft_status` as an optional property and start publishing it.~~ :white_check_mark: 2. Make `new_draft_status` a required property and update subscribers to always expect it. #### Scope - Update the schema in `app/events/merge_requests/draft_state_change_event.rb` to add `new_draft_status to` the required array. - Update subscribers to always expect it - Update relevant specs #### Related 1. https://gitlab.com/gitlab-org/gitlab/-/merge_requests/233605+