Only showing most recent notification from a watched topic?

[tophee (Christoph)]

@david

we did just have a small outage on Meta - it could be that the server went down halfway through publishing your notification.

Not that small, I would say but no, the notification was there, it was published whenever you posted your reply and I saw it via the discourse Android app. Unfortunately, the app doesn’t take you to the post when you tap the android notification so I navigated to meta, tapped my avatar and tapped the notification about your reply. That’s how I got here. But now it’s no longer there:

Wait, there is a pattern here. The above screenshot was taken when I composed my previous reply. Here is what it looks like now:

Notice how I now have the notification for your last reply but the one from merefield is also gone now?

[david (David Taylor)]

Something fishy is definitely going on here… the notification from merefield seems to be missing from the database as well

[5] pry(main)> User.find_by_username("tophee").notifications.order(created_at: :desc).limit(10).pluck(:data).map { |d| JSON.parse(d) }.map {|j| j["display_username"] }
=> ["david", "david", "david", "david", "codinghorror", "zogstrip", "gpetrov", "SidV", "jomaxro", "sam"]

Now that you have a fresh notification, has anything changed @tophee?

[tophee (Christoph)]

This is what it looks like now:

So nothing new went missing (possibly because of the new topic).

[david (David Taylor)]

Oh, this is expected behaviour, I just never noticed it before. If you’re watching a topic, we don’t want you to end up with millions of notifications about a single topic, so we only keep the ‘most recent’ notification.

So after you received the android notification, merefield replied and caused the other notification to be deleted. We don’t delete the notification from Android, only from the web UI.

https://github.com/discourse/discourse/blob/82e45f5485be0deaa606b3536426666f2bf88412/app/services/post_alerter.rb#L339-L342