Summary

Closes #1658

Comment threads currently do not live refresh, so if the original input entity changes, the thread does not update. This is not problematic for most usecases as the entity is usually fixed, but in situations like the firehose, it changes on approval / rejection.

This meant that when approving and rejecting, the old comments stayed in place on the wrong entity.

Steps to test

1. Log in as admin
2. Make 5x posts with the content: adult 1, adult 2, adult 3, adult 4, adult 5
3. Comment on each of these posts (maybe multiple times but not essential) comment 1, comment 2 etc
4. In admin panel, go to firehose
5. First entry should be your new post (adult is a keyword watched by the firehose)
6. Open the comments - be sure the comment is there.
7. Click approve, it should load the next post's comments automatically.
8. Try reject, it should do the same.

Estimated Regression Scope

This affects all comment threads on the side, though only in the way of their change detection. Regressions relating to the updating of threads are possible There was an issue I had during development where it was triggering on the initial input, rather than changes, thus duplicating comments and XHR requests.

added scoped label

added scoped label

added scoped label and automatically removed label

seen at buddy review

assigned to @benhayward.ben

assigned to @edgebal

Seems like the indexing runner is not working correctly on the sandbox.

Looks like this sandbox's indexer is still having issues

In order to avoid unnecessary reloads, can we also check the entity's GUID against the previous value?

added scoped label and automatically removed label

unassigned @edgebal