How can I add a state transition validator to ensure that Priority is set?

Question

We have a default priority called "Unprioritized". I would like to ensure that the priority is set to any other value (besides Unprioritized) when a ticket transitions to another state.

The way I've done this for other fields was to use a "Field Required Validator" to require that the field has been set. However, in this case the field is already set, just not to a useful value. For other fields, you can generally make them optional, in which case the Field Required Validators works fine, but that doesn't seem to be an option for the Priority field.

How can I ensure my users set the priority on a state transition?

Mike Burton_xf49k0 · Answer

One work around is to use a condition instead of a validator, but that is a confusing user experience because it means that the transition button is hidden and users may not know why. Also, it makes drag-and-drop impossible on scrum boards since it hides the target status.

Mike Burton_xf49k0 · Answer

Afaik it does not appear to be possible to set a blank priority: https://community.atlassian.com/t5/Jira-questions/How-do-define-a-blank-or-non-selected-Priority-Field-Value/qaq-p/224401

Dave Theodore [Coyote Creek Consulting] · Answer

Best practices would be to not have the "Unprioritized" Priority and leave the field blank when things are not prioritized. Given that you have things set up the way you do, probably the best solution would be to use the JIRA Workflow Toolbox app. (Hopefully you're not on Cloud.) You should be able to make the regexp Validator do what you need.

I'd recommend eliminating the Unprioritized Priority and leaving the field blank, though. It would be easy to do this with a Bulk Edit, then delete the Priority.