Checklist ships with a Workflow Validator that can be used to enforce checklist completion before a workflow transition. The validator is called "Checklist Validator" and can be customized with the following attributes:
Select the checklist for which the validator applies to.
Select if all items are to be validated or simply the mandatory ones.
Select the issue's resolution(s) for which you want to validate the checklist. This is especially useful when you do not want the validator applied to issues resolved with "Won't fix". If no resolutions are selected, the validation will occur for any resolution.
Use this only if you have a screen which allows you to set the resolution during the transition. If you don't, the validator will compare "Unresolved" with the selected resolution. Since there are no match, the validator will let the transition occur thus giving the impression that the validator is not working.
When the validator is active and attached to a workflow transition, the validator will prevent the transition when the checklist conditions are not met.