HowTo: see a `revision-like` history for JIRA items (e.g. type=test)

Pressacco

Ideally our organization would like to generate a comparison (e.g. similar to Winmerge or TFS Compare) based on:

1. date, or 
2. document revision

Confluence has Page History, but I cannot find a similar feature for JIRA items (e.g. tests case or user story).  I am relatively new to Atlassian products, and would appreciate some guidance.

1. Is there a way to turn this feature on in JIRA?
2. Alternatively, is there an diff-like extension that can be added to JIRA?

BACKGROUND

Our organization is using JIRA+Xray to manage our test plans.  When a test plan is created or modified, the changes need to be approved by another team member.  Unfortunately the Comment History is not useful when any meaningful changes are made to the original document.

Nic Brough -Adaptavist-

There's no function for it in Jira.  It's because Jira is an issue tracker, not a documentation tool.  90% of people who are tracking an issue care nothing for the history of it, just what needs doing now or next.  Of the 10% who do care, 90% of them will only be looking for a very specific single change, and 90% of the rest will be able to read back through the issue history for what they need.  And, since version 4, JQL has been able to hone in on changes a lot more easily.

In short, "diffs" for Jira are not a lot of use to the overwhelming majority of users frequently enough to implement.  I can see it, but I can't class it as any more useful than a "nice to have", given the number of people who would find it useful.