Message missed live isn't restored by refresh if an older message was edited after it

[Styry]

A bot posted a reply while I had the room open. The reply is in the database (bot API returns it, reload shows it), but the open page never showed it, and the reconnect/visibility refresh didn't bring it back either.

Looking at the code, I think this is the cause. refresh_room_controller.js sends the max data-message-updated-at on the page as since:

messageTargetConnected(target) {
  this.#lastLoadedAt = Math.max(this.#lastLoadedAt, target.dataset.messageUpdatedAt || 0)
}

but Rooms::RefreshesController#show uses it to find messages created after that time:

@new_messages = @room.messages.with_presentation.page_created_since(@last_updated_at)

If the page misses the append for message B and then gets a replace for an older message A edited after B was created, since is now later than B's created_at and B is never fetched. Our bot posts a "working…" message, edits it, then posts the answer, so it can hit this.

Also, visibilityChanged() only refreshes if the page was hidden for more than 60 s, so anything missed during a shorter hide isn't fetched unless the cable reconnects.

Possible fix: use data-sort-value (created_at) for since. Edits after that point are still returned by page_updated_since. And refresh on every return to the page:

-const REFRESH_AFTER_HIDDEN_TIMEOUT = 60_000
+const REFRESH_AFTER_HIDDEN_TIMEOUT = 0

   messageTargetConnected(target) {
-    this.#lastLoadedAt = Math.max(this.#lastLoadedAt, target.dataset.messageUpdatedAt || 0)
+    this.#lastLoadedAt = Math.max(this.#lastLoadedAt, target.dataset.sortValue || 0)
   }

Pending messages aren't refresh-room targets, so they don't affect since. A small threshold instead of 0 would also work.

We've patched our install this way. Can send a PR if this looks right.