commit dee184926e9419a2032a608f6301b17286b99cba
author Edwin Kempin <ekempin@google.com> Mon Feb 12 10:25:04 2024 +0000
committer Edwin Kempin <ekempin@google.com> Mon Feb 12 11:48:08 2024 +0000
tree b1fbd861bbd20a555c27a793cdca0f51e61639e9
parent 74a03beeb43dbbec6d99b708a1fa0a875cf887cd

Add owner to attention set only when a reply requires the attention of the owner

So far the change owner (and the uploader) have been added to the
attention set whenever someone replied on the change, even if the reply
was on an outdated patch set and didn't impact the current change state
(e.g. if someone voted on an outdated patch set and none of the votes
were copied to the current patch set).

With this change we update the attention set update logic to:
* Only add the change owner and uploader to the attention set if a reply
  requires their attention which is the case if votes on the current
  patch set were updated (either directly or through vote copying), a
  change message was posted, new comments were posted or a
  work-in-progress change was marked as ready.
* Keep the replying user in the attention set (or add them to the
  attention set if they are not in the attention set yet) if they voted
  on an outdated patch set and not all of their votes got copied to the
  current patch set, so that they are made aware that they need to
  re-apply their vote on the current patch set. In this case the reason
  for the user to be in the attention set is set to "Some votes were not
  copied to the current patch set".
* For bot replies: Only add the change owner and uploader to the
  attention set if negative votes got updated on the current patch set
  (either directly or through vote copying).

This means to decide whether or not the change owner and uploader should
be added to the attention set and whether or not the replying user
should be kept in the attention set or be added to it, depends on the
result of the approval copying which is done in PostReviewOp (whether or
not approvals that were applied on outdated patch sets were copied to
the current patch set).

This means which attention set updates need to be performed depends on
the result of PostReviewOp, which is not available yet at the moment
when we create the BatchUpdate ops to update the attention set, but only
when the attention update ops are being executed through BatchUpdate (at
this point the preceding PostReviewOp which is part of the same
BatchUpdate has been executed and can be asked for its result).

To make attention set updates that are based on the result of the
preceding PostReviewOp, we add attention set updates with conditions
when creating the ops for the BatchUpdate, that are only being checked
when the ops are being executed (also see change Iba9e5617f which added
support for conditional attention set updates).

The new behaviour for attention set updates on reply is this:
1. If the reply of a human user changes the current change state (it
   updates votes on the current patch set, posts a change message, posts
   new comments or marks a work-in-progress as ready), the change owner
   and the uploader are added to the attention set and the replying user
   is removed from the attention set. This means no-op (empty) replies
   that do not change the current change state no longer update the
   attention set.
2. If the reply of a human user only applies votes on an outdated patch
   set and none of these votes is copied to the current patch set, the
   change owner and uploader are not added to the attention set and the
   replying user is kept in the attention set or is added to it to make
   them aware that they need to re-apply votes on the current patch set
   (the reason for being in the attention set is updated accordingly).
3. If the reply of a bot user results in a negative vote on the current
   patch set, the change owner and uploader are added to the attention
   set.
4. If the reply of a bot doesn't result in a negative vote on the
   current patch set (e.g. because the bot voted on an outdated patch
   set and the vote was not copied to the current patch set), the change
   owner and uploader are not added to the attention set.

Note, the behaviour for bot users is different than for human users
since we have simplied rules for them (the change owner and uploader are
only added to the attention set if the bot voted negatively).

Bug: Google b/262017722
Release-Notes: Changed attention set logic to add owner and uploader to attention set only when a reply requires the attention of the m
Change-Id: I1c87439c1aa612535c7270cec9ea4a8e4ba3534a
Signed-off-by: Edwin Kempin <ekempin@google.com>