How do you trigger an Epic to transition, only when ALL of its Jiras have been transitioned? Edited

[Victor Grazi]

We would like to automatically transition Epics based on the transitions of the Jiras (of any type) belonging to that Epic.

For example, let's say we have the following statuses:

Backlog, Development, Ready for Release

1. So if I transition one issue from "Backlog" to "Development", then that Epic (as a unit) is clearly in "Development", so the Epic should automatically transition to "Development" when any one of its Jiras is transitioned to "Development".

2. However if I transition one issue from "Development" to "Ready for Release", well then the whole Epic is not truly ready for release yet, until all of the underlying Jiras are ready. So in this case, the Epic should automatically transition to "Ready for Release" only when all of its issues are transitioned to "Ready for Release".

Case 1 we can handle with a "post function" trigger. But case 2 is where we are struggling.

Is there any way to trigger an epic transition to a status, only when all of its Jiras have been transitioned to that status?