SignalRAttribute's HubName property has no validation

[look-im-not-your-daddy]

I'm not sure where this validation should occur (I believe during the functions' discovery/inspection/load), but it doesn't happen and when you call your injected IAsyncCollector<SignalRMessage>.AddAsync(message) having it being setup with an invalid HubName (which till today I didn't know about the existence of such thing) you'll get an HTTP 400 on your App Insights with no reasoning. Very hard to trace the reason behind it.

    public static class JobExecutionStatusUpdated
    {
        public const string EventName = nameof(JobExecutionStatusUpdated);

        [FunctionName(nameof(JobExecutionStatusUpdated))]
        public static Task Run
        (
            [ServiceBusTrigger("job_execution_status_updated")] JobExecutionStatusUpdate update,
            [SignalR(HubName = "myapp-notifications")] IAsyncCollector<SignalRMessage> signalR,
            ILogger logger
        )
        {
            logger.LogInformation($"*** [{nameof(JobExecutionStatusUpdated)}] received a message from queue 'job_execution_status_updated': '{JsonConvert.SerializeObject(update)}'");

            var message = new SignalRMessage
            {
                UserId = "0123-3456789",
                Target = EventName,
                Arguments = new[] { update }
            };

            return signalR.AddAsync(message);
        }
    }

Apparently hyphen is not welcome in a HubName (which I have no problem with) but I believe it should be stated somewhere in the docs or validated in the functions' discovery/inspection/load phase with the latter being very appropriate.

If stated in the docs somewhere, please point me to it.