问如何识别JavaScript客户端上的SignalR核心集线器错误？

EN

private async Task SendInvocationError(string invocationId, HubConnectionContext connection, string errorMessage)
{
    if (string.IsNullOrEmpty(invocationId))
    {
        return;
    }

    await connection.WriteAsync(CompletionMessage.WithError(invocationId, errorMessage));
}

if (!await IsHubMethodAuthorized(scope.ServiceProvider, connection, descriptor, hubMethodInvocationMessage.Arguments, hub))
{
    Log.HubMethodNotAuthorized(_logger, hubMethodInvocationMessage.Target);
    await SendInvocationError(hubMethodInvocationMessage.InvocationId, connection,
        $"Failed to invoke '{hubMethodInvocationMessage.Target}' because user is unauthorized");
    return;
}

var errorMessage = ErrorMessageHelper.BuildErrorMessage($"Failed to invoke '{bindingFailureMessage.Target}' due to an error on the server.",
    bindingFailureMessage.BindingFailure.SourceException, _enableDetailedErrors);
return SendInvocationError(bindingFailureMessage.InvocationId, connection, errorMessage);

HubConnection.prototype.connectionClosed = function (error) {
    this.logger.log(_ILogger__WEBPACK_IMPORTED_MODULE_2__["LogLevel"].Debug, "HubConnection.connectionClosed(" + error + ") called while in state " + this.connectionState + ".");
    // Triggering this.handshakeRejecter is insufficient because it could already be resolved without the continuation having run yet.
    this.stopDuringStartError = this.stopDuringStartError || error || new Error("The underlying connection was closed before the hub handshake could complete.");
    // If the handshake is in progress, start will be waiting for the handshake promise, so we complete it.
    // If it has already completed, this should just noop.
    if (this.handshakeResolver) {
        this.handshakeResolver();
    }
    this.cancelCallbacksWithError(error || new Error("Invocation canceled due to the underlying connection being closed."));
    
    ...
};