FEATURE: High priority bookmark reminder notifications (#9290)

Introduce the concept of "high priority notifications" which include PM and bookmark reminder notifications. Now bookmark reminder notifications act in the same way as PM notifications (float to top of recent list, show in the green bubble) and most instances of unread_private_messages in the UI have been replaced with unread_high_priority_notifications.

The user email digest is changed to just have a section about unread high priority notifications, the unread PM section has been removed.

A high_priority boolean column has been added to the Notification table and relevant indices added to account for it.

unread_private_messages has been kept on the User model purely for backwards compat, but now just returns unread_high_priority_notifications count so this may cause some inconsistencies in the UI.

spec/models/user_spec.rb

@@ -1779,7 +1779,7 @@ describe User do
   end
 
   describe '#publish_notifications_state' do
-    it 'should publish the right message' do
+    it 'should publish the right message sorted by ID desc' do
       notification = Fabricate(:notification, user: user)
       notification2 = Fabricate(:notification, user: user, read: true)
 
@@ -1788,8 +1788,41 @@ describe User do
       end.first
 
       expect(message.data[:recent]).to eq([
-                                            [notification2.id, true], [notification.id, false]
-                                          ])
+        [notification2.id, true], [notification.id, false]
+      ])
+    end
+
+    it 'floats the unread high priority notifications to the top' do
+      notification = Fabricate(:notification, user: user)
+      notification2 = Fabricate(:notification, user: user, read: true)
+      notification3 = Fabricate(:notification, user: user, notification_type: Notification.types[:private_message])
+      notification4 = Fabricate(:notification, user: user, notification_type: Notification.types[:bookmark_reminder])
+
+      message = MessageBus.track_publish("/notification/#{user.id}") do
+        user.publish_notifications_state
+      end.first
+
+      expect(message.data[:recent]).to eq([
+        [notification4.id, false], [notification3.id, false],
+        [notification2.id, true], [notification.id, false]
+      ])
+    end
+
+    it "has the correct counts" do
+      notification = Fabricate(:notification, user: user)
+      notification2 = Fabricate(:notification, user: user, read: true)
+      notification3 = Fabricate(:notification, user: user, notification_type: Notification.types[:private_message])
+      notification4 = Fabricate(:notification, user: user, notification_type: Notification.types[:bookmark_reminder])
+
+      message = MessageBus.track_publish("/notification/#{user.id}") do
+        user.publish_notifications_state
+      end.first
+
+      expect(message.data[:unread_notifications]).to eq(1)
+      # NOTE: because of deprecation this will be equal to unread_high_priority_notifications,
+      #       to be remonved in 2.5
+      expect(message.data[:unread_private_messages]).to eq(2)
+      expect(message.data[:unread_high_priority_notifications]).to eq(2)
     end
   end
 
@@ -1821,6 +1854,7 @@ describe User do
   end
 
   describe "#unread_notifications" do
+    fab!(:user) { Fabricate(:user) }
     before do
       User.max_unread_notifications = 3
     end
@@ -1830,14 +1864,32 @@ describe User do
     end
 
     it "limits to MAX_UNREAD_NOTIFICATIONS" do
-      user = Fabricate(:user)
-
       4.times do
         Notification.create!(user_id: user.id, notification_type: 1, read: false, data: '{}')
       end
 
       expect(user.unread_notifications).to eq(3)
     end
+
+    it "does not include high priority notifications" do
+      Notification.create!(user_id: user.id, notification_type: 1, read: false, data: '{}')
+      Notification.create!(user_id: user.id, notification_type: Notification.types[:private_message], read: false, data: '{}')
+      Notification.create!(user_id: user.id, notification_type: Notification.types[:bookmark_reminder], read: false, data: '{}')
+
+      expect(user.unread_notifications).to eq(1)
+    end
+  end
+
+  describe "#unread_high_priority_notifications" do
+    fab!(:user) { Fabricate(:user) }
+
+    it "only returns an unread count of PM and bookmark reminder notifications" do
+      Notification.create!(user_id: user.id, notification_type: 1, read: false, data: '{}')
+      Notification.create!(user_id: user.id, notification_type: Notification.types[:private_message], read: false, data: '{}')
+      Notification.create!(user_id: user.id, notification_type: Notification.types[:bookmark_reminder], read: false, data: '{}')
+
+      expect(user.unread_high_priority_notifications).to eq(2)
+    end
   end
 
   describe "#unstage!" do