SignalR Core StartAsync() CancellationToken not respected?

Seems that the AspNetCore Signalr Client doesn’t respect the cancellationtoken passed into the StartAsync() method. It will throw appropriately if the CTS timeout is sufficiently short (e.g., 1 millisecond);

Using this version of ASP.NET Core 3 Preview 5

var cts = new CancellationTokenSource(TimeSpan.FromSeconds(1));
           var _hubConnection = new HubConnectionBuilder()
                .WithUrl(".WithUrl("http://slowwly.robertomurray.co.uk/delay/5000/url/http://www.google.co.uk")") //artificially slow, response times of ~5 seconds before a 404 is returned
                .Build();
           await _hubConnection.StartAsync(cts.Token);

Expected behavior

StartAsync() should throw an OperationCancelledException after 1 second. Any negotiation or handshake should be aborted if it was not already successfully completed within 1 second.

Current behavior

StartAsync() will wait until an HttpRequestException (in this case, a 404 after 5 seconds) is thrown or the connection succeeds. An OperationCancelledException is never thrown.

[BalintFarkas]

Hey @mikaelm12 -

sure, we’d be delighted to! We have already created fixes for 1.1.0 and 1.0.4, and will create one for the current 3.x version tomorrow with my colleague @danielloczi, then submit PRs. Would that be acceptable?

[mikaelm12]

@BalintFarkas Since you already have the fix in your fork this issue seems like a great candidate for a community contribution 😄 . Would you be interested?