public void Assert_Multiply() { var example = new ExampleController(CalculatorMock.GetMock()); var response = example.Multiply("3", "3"); Assert.IsNotNull(response); Assert.AreEqual("9", ((Response)((OkObjectResult)response).Value).ResponseData); response = example.Multiply("3", "a"); Assert.IsNotNull(response); Assert.IsInstanceOf <BadRequestObjectResult>(response); }