public void RfidDectected_RfidDetectedInAvailableState_ChargeControlConnectedButStartChargeFails_DisplayConnectionError() { //arrange _chargeControl.IsConnected().Returns(true); _chargeControl .When(c => c.StartCharge()) .Do(c => throw new NotConnectedException()); //act _rfidReader.RfidDetectedEvent += Raise.Event <EventHandler <int> >(_rfidReader, 123); //assert _display.Received().ShowConnectionError(); }