Merge pull request #156 from GetStream/feature/uni-116-null-argument-for-userid-in

Add potential fix for occasional null ref UserId when constucting Tra…

Author: sierpinskid

Packages/StreamVideo/Runtime/Core/LowLevelClient/RtcSession.cs

@@ -572,9 +572,13 @@ private IEnumerable<TrackSubscriptionDetails> GetDesiredTracksDetails()
 
                 foreach (var trackType in trackTypes)
                 {
+                    //StreamTODO: UserId is sometimes null here
+                    //This was before changing the IUpdateableFrom<CallParticipantResponseInternalDTO, StreamVideoCallParticipant>.UpdateFromDto
+                    //to extract UserId from User obj
+                    
                     yield return new TrackSubscriptionDetails
                     {
-                        UserId = participant.UserId,
+                        UserId = GetUserId(participant),
                         SessionId = participant.SessionId,
                         TrackType = trackType,
                         Dimension = requestedVideoResolution.ToVideoDimension()
@@ -583,6 +587,23 @@ private IEnumerable<TrackSubscriptionDetails> GetDesiredTracksDetails()
             }
         }
 
+        //StreamTodo: remove this, this is a workaround to Null UserId error
+        private string GetUserId(IStreamVideoCallParticipant participant)
+        {
+            if (!string.IsNullOrEmpty(participant.UserId))
+            {
+                return participant.UserId;
+            }
+
+            if (participant.User == null || string.IsNullOrEmpty(participant.User.Id))
+            {
+                throw new Exception(
+                    $"Both {nameof(IStreamVideoCallParticipant.UserId)} and {nameof(IStreamVideoCallParticipant.User)} ID are null or empty. No way to get the user ID");
+            }
+
+            return participant.User.Id;
+        }
+
         private VideoResolution GetRequestedVideoResolution(IStreamVideoCallParticipant participant)
         {
             if (participant == null || participant.SessionId == null)

Packages/StreamVideo/Runtime/Core/StatefulModels/StreamVideoCallParticipant.cs

@@ -142,6 +142,18 @@ void IUpdateableFrom<CallParticipantResponseInternalDTO, StreamVideoCallParticip
             Role = dto.Role;
             User = cache.TryCreateOrUpdate(dto.User);
             UserSessionId = dto.UserSessionId;
+
+            if (string.IsNullOrEmpty(UserId) && User != null)
+            {
+                UserId = User.Id;
+            }
+            
+            //StreamTodo: investigate why we either update UserId or User object
+            //Depending on the update source we'll end up with one being empty
+            //We can take UserId from user obj, but we can't easily get User obj give UserId in dto
+            //Ideally, we'd only expose the User object -> check if this is possible
+            
+            //StreamTodo: verify if we're using every piece of data received from API/SFU responses to update this object
         }
 
         internal void LoadCustomDataFromOwningCallCustomData(Dictionary<string, object> participantCustomData)