Unable to Setup Asynchronous QTcpSocket Connection with QApplications

#include <QApplication>
#include <QDebug>
#include <QTcpSocket>
#include <QTimer>

#include <cstdint>

static const char * const kHostName = "127.0.0.1";
static const std::uint16_t kPort = 2344;

int main(int argc, char* argv[])
{
   QApplication app(argc, argv);   // change type to QCoreApplication for it to work

   QTcpSocket socket;

   QObject::connect(&socket, &QTcpSocket::stateChanged, [](QAbstractSocket::SocketState state)
   {
      qDebug() << "state changed:" << state;
   });

   QObject::connect(&socket, static_cast<void(QTcpSocket::*)(QAbstractSocket::SocketError)>(&QTcpSocket::error), [](QAbstractSocket::SocketError error)
   {
      qDebug() << "error:" << error;
   });

   socket.connectToHost(kHostName, kPort);

   return app.exec();
}

state changed: QAbstractSocket::HostLookupState
state changed: QAbstractSocket::ConnectingState

state changed: QAbstractSocket::UnconnectedState
error: QAbstractSocket::SocketTimeoutError

state changed: QAbstractSocket::HostLookupState
state changed: QAbstractSocket::ConnectingState
state changed: QAbstractSocket::UnconnectedState
error: QAbstractSocket::ConnectionRefusedError

void QAbstractSocket::connectToHost(const QString &hostName, quint16 port, QIODevice::OpenMode openMode = ReadWrite, QAbstractSocket::NetworkLayerProtocol protocol = AnyIPProtocol)

Attempts to make a connection to hostName on the given port. The protocol parameter can be used to specify which network protocol to use (eg. IPv4 or IPv6).

The socket is opened in the given openMode and first enters HostLookupState, then performs a host name lookup of hostName. If the lookup succeeds, hostFound() is emitted and QAbstractSocket enters ConnectingState. It then attempts to connect to the address or addresses returned by the lookup. Finally, if a connection is established, QAbstractSocket enters ConnectedState and emits connected().

At any point, the socket can emit error() to signal that an error occurred.

hostName may be an IP address in string form (e.g., "43.195.83.32"), or it may be a host name (e.g., "example.com"). QAbstractSocket will do a lookup only if required. port is in native byte order.