Whenever talking about versioning, different things may come to the surface that may be somehow related.
To what versioning are you referring to exactly? Requirements versioning, test versioning?
Are you talking about tracking changes on your artifacts or on having explicit versions each time you change an artifact?
As preliminary information, JIRA issues are assigned to a given version, by specifying the "Fix Version" field.
Besides this, JIRA ensures that changes are tracked under the History section, so you know who changed what and when.
So, if you have a requirement (e.g. a story) for version 1.0 and you wish to change it somehow in another posterior version (e.g. v2.0), normally you will have to create another requirement issue to specify the new behaviour.
However, if you are changing the specification during the development lifecycle of that requirement, you can simply update its description and use JIRA workflows to guarantee that is being handled properly.
If you make changes in some of the attributes of a issue, it gets tracked in the History changes; however, there is no increment in the version (not in any other field) of the requirement because it is used for another purpose: to tell for which version you're delivering it.
Versioning of Tests work in the same way as versioning of other issue types in JIRA. Since Xray's Tests are JIRA issues, we follow the same approach so your users work in the same manner.
In other words, this means:
Having in mind that Test issues are like reusable test case templates, should you assign Test issues to a given version? If so, what would be the purpose of it?
The test specification has a lifecycle; although your tests may live accross many versions of your project, they're..
Xray support this feature in this way, which we think is way more advanced: