Is there any way to configure groovy script for an action in response to status transition to COMPLETE status using validators

[Nic Brough -Adaptavist-]

Possibly, but you really don't want to do it with validators.

You should only do things that make changes in transitions during post-functions (or listeners that happen even later).  Validators are totally the wrong place.

So, the question is - what do you want to do when the issue moves to complete?

[Jyotiprakash Nayak]

is it possible to verify  Epic->some field contains value, when Task " is set to completed.

The task should not be able to be set to Completed, if the Epic->that field is not set.

[Nic Brough -Adaptavist-]

What does "epic some field" mean?

[Jyotiprakash Nayak]

it means any field in that epic

[Jyotiprakash Nayak]

the requirement is that whenever a task is set to complete ,it should inspect the value of a field named ' Documentation Update' in the parent epic to which the particular task is linked . In case the value is not provided, the transition should not be allowed.

[Nic Brough -Adaptavist-]

That's another requirement again.  The best way to do that is in a "condition", as that would stop the user starting the process to change the status.

However, neither conditions or validators can be scripted on Cloud yet.  So I don't think there's any way to do this.