To add Subtasks JQL validator, go to the transition of your workflow, switch to Validators tab and click on Add Validator button.
Select JEP - Subtasks JQL validator and click Add button
Type the JQL that the subtasks of the issue should match to proceed the transition. Also type the message that should be displayed if the JQL does not match.
- Match Type: Select type of matching strategy.
- ALL_MATCH: All subtasks should match given JQL
- ANY_MATCH: At least one of the subtasks should match given JQL
- NO_MATCH: None of the subtasks should match JQL
- JQL: Type your JQL here
- Message: The message that should be see if JQL statement does not match
- Skip when no subtasks: Enable this option, to skip validator if there are no subtasks for the issue.
Click Add button, and that's it.
If the subtasks of the issue do not match the (given) JQL, then the transition is prohibited and gives the (given) error message.
Do not forget to publish the workflow!