Checklist For Jira Cloud comes with two inbuilt checklist validators which you could use to block Issue transition from one state to another.
The two Validators are :
- All Checklist items are complete
- All mandatory checklist items are completed
Adding these conditions to your workflow will make it mandatory for the condition to be valid before the issue can transition from one status to another.
Adding the checklist validator to the workflow
Select 
> Issues.
Click Workflows and then Edit the relevant workflow.
In diagram mode, select the transition arrow. In text mode, select the transition’s name from the Transitions (id) column.
Click on Validators>Add Validator.
Select the checklist validator that you want and Add.
