public async Task StartAsync()

in src/Microsoft.Azure.SignalR.Common/ServiceConnections/Internal/WebSocketsTransport.cs [108:155]

• 37 lines of code
• 5 McCabe index (conditional complexity)

    public async Task StartAsync(Uri url, CancellationToken cancellationToken = default)
    {
#if NET6_0_OR_GREATER
        ArgumentNullException.ThrowIfNull(url);
#else
        if (url == null)
        {
            throw new ArgumentNullException(nameof(url));
        }
#endif
        var resolvedUrl = ResolveWebSocketsUrl(url);

        string accessToken = null;
        // We don't need to capture to a local because we never change this delegate.
        if (_accessTokenProvider != null)
        {
            accessToken = await _accessTokenProvider.ProvideAsync();
            if (!string.IsNullOrEmpty(accessToken))
            {
                _webSocket.Options.SetRequestHeader("Authorization", $"Bearer {accessToken}");
            }
        }

        Log.StartTransport(_logger, _webSocketMessageType, resolvedUrl);

        try
        {
            await _webSocket.ConnectAsync(resolvedUrl, cancellationToken);
        }
        catch (Exception e)
        {
            _webSocket.Dispose();
            throw e.WrapAsAzureSignalRException(accessToken);
        }

        Log.StartedTransport(_logger);

        // Create the pipe pair (Application's writer is connected to Transport's reader, and vice versa)
        var options = DefaultOptions;
        var pair = DuplexPipe.CreateConnectionPair(options, options);

        _transport = pair.Transport;
        _application = pair.Application;

        // TODO: Handle TCP connection errors
        // https://github.com/SignalR/SignalR/blob/1fba14fa3437e24c204dfaf8a18db3fce8acad3c/src/Microsoft.AspNet.SignalR.Core/Owin/WebSockets/WebSocketHandler.cs#L248-L251
        Running = ProcessSocketAsync(_webSocket);
    }