The underlying connection was closed before the hub handshake could complete.

[nayefradwi]

The underlying connection was closed before the hub handshake could complete.

[nayefradwi]

After investigating this issue, It seems that the handshake request is being sent without the authorization header, which in the backend I am working with is required to establish the connection.

I tried to do something like this but still did not fix the issue

    MessageHeaders headers = MessageHeaders();
    headers.setHeaderValue(AuthInterceptor.authorizedHeader,
        "Bearer ${GetIt.I<ShopperApiClient>().accessToken}");
    HubConnection connection = HubConnectionBuilder()
        .withUrl(
          AppConfig.signalrUrl,
          options: HttpConnectionOptions(
            logger: transportProtLogger,
            logMessageContent: !AppConfig.isProd,
            headers: headers,
            skipNegotiation: true,
            requestTimeout: 120000,
            transport: HttpTransportType.WebSockets,
            accessTokenFactory: () async {
              String accessToken = GetIt.I<ShopperApiClient>().accessToken;
              return accessToken;
            },
          ),
        )
        .withAutomaticReconnect(retryDelays: delaysInMilliSeconds)
        .configureLogging(hubProtLogger)
        .withHubProtocol(JsonHubProtocol())
        .build();
    return connection;

I have noticed that the first request and the negotiation both have the access token in their headers, just the handshake request does not have it and this causes the error "The underlying connection was closed before the hub handshake could complete."