public void AddIpAddressTest() { string newAddress = "4.4.4.4/4"; var mock = new Mock <INetworkAddressRepository>(); var serviceInstance = new HomeService(mock.Object); mock.Setup(a => a.AddIpAddressToDataBase(It.IsAny <string>())).Verifiable(); serviceInstance.AddIpAddress(newAddress); mock.Verify(); var actual = mock.Invocations.Count; Assert.AreEqual(1, actual); }