VRFS-2539 protect against error during notification load if the related session is missing / clean up the notifications of nonexistent sessions

ruby/lib/jam_ruby/models/music_session.rb

@@ -427,6 +427,7 @@ module JamRuby
     # returns one user history per user, with instruments all crammed together, and with total duration
     def unique_user_histories
 
+      # only get the active users if the session is in progress
       user_filter = "music_sessions_user_history.session_removed_at is null" if self.session_removed_at.nil?
 
       MusicSessionUserHistory

ruby/lib/jam_ruby/models/notification.rb

@@ -42,7 +42,7 @@ module JamRuby
     # used for persisted notifications
     def formatted_msg
       # target_user, band, session, recording, invitation, join_request = nil
-      source_user, band = nil
+      source_user, band, session = nil
 
       unless self.source_user_id.nil?
         source_user = User.find(self.source_user_id)
@@ -53,7 +53,12 @@ module JamRuby
       end
 
       unless self.session_id.nil?
-        session = MusicSession.find(self.session_id)
+        session = MusicSession.find_by_id(self.session_id)
+
+        # remove all notifications related to this session if it's not found
+        if session.nil?
+          Notification.delete_all "(session_id = '#{session_id}')"
+        end
       end
 
       self.class.format_msg(self.description, {:user => source_user, :band => band, :session => session})

web/app/assets/javascripts/notificationPanel.js

@@ -207,19 +207,24 @@
       isLoading = true;
       // retrieve pending notifications for this user
       rest.getNotifications(buildParams())
-            .done(function(response) {
-                updateNotificationList(response);
-                isLoading = false;
-            })
-            .fail(function() {
-                isLoading = false;
-                app.ajaxError();
-            })
+        .done(function(response) {
+            updateNotificationList(response);
+            isLoading = false;
+        })
+        .fail(function() {
+            isLoading = false;
+            app.ajaxError();
+        })
     }
 
     function updateNotificationList(response) {
       $.each(response, function(index, val) {
 
+        // this means the session no longer exists
+        if (response.fan_access == null && response.musician_access == null) {
+          return;
+        }
+
         if(val.description == context.JK.MessageType.TEXT_MESSAGE) {
           val.formatted_msg = textMessageDialog.formatTextMessage(val.message.substring(0, 200), val.source_user_id, val.source_user.name, val.message.length > 200).html();
         }