public void ArpScanner_GetRespondingMachines_Starts_ArpScan_Process() { // Arrange IProcessWrapper mockProcessWrapper = GetMockProcessWrapper(new string[] { null }); _processWrapperFactory.Stub(x => x.GetNewProcessWrapper()).Return(mockProcessWrapper); var sut = new ArpScanner(_processWrapperFactory); // Act sut.GetRespondingMachines(); // Assert mockProcessWrapper.AssertWasCalled(x => x.Start(), options => options.Repeat.Once()); }