Mixing QT with Google Test

[JuliusCaesar]

Hey guys,
I'm using QT with google test.
Some of my functions to test involve signals and slots (like Bluetooth in my case).
However teese do no seam to work in GTEST

The basic setup

My class QT_BT_ExampleScan should perform a scan for available bluetooth devices in the background => that's why it's running in it's own thread.

class QT_BT_ExampleScan : public QThread
{
Q_OBJECT
public:
QT_BT_ExampleScan ();

 private:
  std::unique_ptr<QBluetoothDeviceDiscoveryAgent> m_pDeviceDiscoveryAgent;

  void run() override;
   public slots:
   void addDevice(const QBluetoothDeviceInfo&);
};

QT_BT_ExampleScan ::QT_BT_ExampleScan ();
{
   m_pDeviceDiscoveryAgent = std::make_unique<QBluetoothDeviceDiscoveryAgent>();
    if (!connect(m_pDeviceDiscoveryAgent.get(), SIGNAL(deviceDiscovered(QBluetoothDeviceInfo)),
      this, SLOT(addDevice(QBluetoothDeviceInfo))))
    {
      qWarning() << "Failed to connect";
    }
}

void QT_BT_ExampleScan ::run()
  {
     startDeviceDiscovery();
      int iRes = exec();
      qDebug() << "Thread " << currentThreadId() << " finnished with result " << iRes;
  }

 void QT_BT_ExampleScan::addDevice(const QBluetoothDeviceInfo& info)
  {
    qDebug() << "Adding device " << info.name();
    QBluetoothLocalDevice::Pairing pairingStatus = m_pLocalBluetoothDevice->pairingStatus(info.address());
    if (pairingStatus == QBluetoothLocalDevice::Paired || pairingStatus == QBluetoothLocalDevice::AuthorizedPaired)
    {
      qDebug() << "Device with address" << info.address() << "already paired";
    }
    else
    {
      qDebug() << "Device with address " << info.address() << "not yet paired";
    }
  }

1) In the GTest case it is called via

int main(int argc, char* argv[])
{

  ::testing::InitGoogleTest(&argc, argv);
  QGuiApplication app(argc, argv);

  int res = RUN_ALL_TESTS();
  return  res;

}

with fixture

class TestBluetooth : public ::testing::Test
{
public:

};

TEST_F(TestBluetooth, BT_QT_Example)
{
  auto pThread = std::make_unique<QT_BT_ExampleScan>();
  pThread->start();
  const auto sleepTime = 20s;
  std::this_thread::sleep_for(sleepTime);
}

However in this case, no QT events are fired/received.

2) Modification of the main()

int main(int argc, char* argv[])
{

  ::testing::InitGoogleTest(&argc, argv);

  QGuiApplication app(argc, argv);
  QT_BT_ExampleScan test;
  test.start();
  return app.exec();
}

This here fires up events nicely. However Gtest is not running any longer.

Problem assumption for 1) case

=>for signals/slots the eventloop must be running. This only seams to be triggers by

QGuiApplication app(argc, argv);
app.exec()

=>My Idea how to solve this:

=> Keep calling app.exec() but move GTest to a separate thread.

int main(int argc, char* argv[])
{
::testing::InitGoogleTest(&argc, argv);
QGuiApplication app(argc, argv);
  auto pGTestThread = std::make_unique<GTestThread>();
  return app.exec();
}

class GTestThread : protected QThread
{
public:
  explicit GTestThread();

  ~GTestThread();

private:
  void run() override;
};

GTestThread::GTestThread()
{
  start();
}

GTestThread::~GTestThread()
{
  if (isRunning())
  {
    exit(0);
    wait();
  }
}

void GTestThread::run()
{
  RUN_ALL_TESTS();
}

However this does not work either. GTest is running but no signals/slots are working again.
Do you know why? The eventloop should be up by the end of main(). Why are no events fired?

could you help me out here?