DEV: Add push notification filtering to MessageBus alerts (#25965)

app/services/post_alerter.rb

@@ -38,13 +38,20 @@ class PostAlerter
       DiscourseEvent.trigger(:pre_notification_alert, user, payload)
 
       if user.allow_live_notifications?
-        payload =
-          DiscoursePluginRegistry.apply_modifier(
-            :post_alerter_live_notification_payload,
-            payload,
-            user,
-          )
-        MessageBus.publish("/notification-alert/#{user.id}", payload, user_ids: [user.id])
+        send_notification =
+          DiscoursePluginRegistry.push_notification_filters.all? do |filter|
+            filter.call(user, payload)
+          end
+
+        if send_notification
+          payload =
+            DiscoursePluginRegistry.apply_modifier(
+              :post_alerter_live_notification_payload,
+              payload,
+              user,
+            )
+          MessageBus.publish("/notification-alert/#{user.id}", payload, user_ids: [user.id])
+        end
       end
 
       push_notification(user, payload)

plugins/chat/app/jobs/regular/chat/notify_watching.rb

@@ -76,7 +76,17 @@ module Jobs
         }
 
         if membership.desktop_notifications_always? && !membership.muted?
-          ::MessageBus.publish("/chat/notification-alert/#{user.id}", payload, user_ids: [user.id])
+          send_notification =
+            DiscoursePluginRegistry.push_notification_filters.all? do |filter|
+              filter.call(user, payload)
+            end
+          if send_notification
+            ::MessageBus.publish(
+              "/chat/notification-alert/#{user.id}",
+              payload,
+              user_ids: [user.id],
+            )
+          end
         end
 
         if membership.mobile_notifications_always? && !membership.muted?

plugins/chat/spec/jobs/regular/chat/notify_watching_spec.rb

@@ -85,6 +85,16 @@ RSpec.describe Jobs::Chat::NotifyWatching do
       end
     end
 
+    context "with push_notification_filter registered to block push notifications" do
+      after { DiscoursePluginRegistry.reset_register!(:push_notification_filters) }
+
+      it "doesn't send notification alert via MessageBus" do
+        Plugin::Instance.new.register_push_notification_filter { |user, payload| false }
+
+        expect(notification_messages_for(user2)).to be_empty
+      end
+    end
+
     context "when the channel is muted via membership preferences" do
       before { membership2.update!(muted: true) }
 

spec/services/post_alerter_spec.rb

@@ -1188,21 +1188,29 @@ RSpec.describe PostAlerter do
     end
 
     describe "DiscoursePluginRegistry#push_notification_filters" do
+      after { DiscoursePluginRegistry.reset_register!(:push_notification_filters) }
+
       it "sends push notifications when all filters pass" do
+        evil_trout.update!(last_seen_at: 10.minutes.ago)
         Plugin::Instance.new.register_push_notification_filter { |user, payload| true }
 
-        expect { mention_post }.to change { Jobs::PushNotification.jobs.count }.by(1)
-        DiscoursePluginRegistry.reset!
+        alerts =
+          MessageBus.track_publish("/notification-alert/#{evil_trout.id}") do
+            expect { mention_post }.to change { Jobs::PushNotification.jobs.count }.by(1)
+          end
+
+        expect(alerts).not_to be_empty
       end
 
       it "does not send push notifications when a filters returns false" do
         Plugin::Instance.new.register_push_notification_filter { |user, payload| false }
-        expect { mention_post }.not_to change { Jobs::PushNotification.jobs.count }
 
-        events = DiscourseEvent.track_events { mention_post }
-        expect(events.find { |event| event[:event_name] == :push_notification }).not_to be_present
+        alerts =
+          MessageBus.track_publish("/notification-alert/#{evil_trout.id}") do
+            expect { mention_post }.not_to change { Jobs::PushNotification.jobs.count }
+          end
 
-        DiscoursePluginRegistry.reset!
+        expect(alerts).to be_empty
       end
     end