I have already tried Sub-Task Blocking Condition to prevent closing parent issue when any of the sub-task is not closed. It just hides the transition status if any sub-task is not closed.
Now I'm looking for some validator which validates if all the sub-tasks are closed if anyone tries to close the parent issue, and if any of the sub-task is not closed then prompt a simple message to notify to close the sub-tasks before closing parent.
Simply, I'm just looking to promote a message while closing parent issue if sub-task is not closed. Please let me know if we can do this without installing any add-ons/plugins.
Any help is appreciated!