public void Fibinacci_ReturnsOk() { var expected = new List <double> { 1, 1, 2, 3, 5, 8, 13, 21, 34, 55 }; validationService.IsValidApiToken(Arg.Any <string>()).Returns(true); mathService.GetFibonacci(Arg.Any <int>()).Returns(expected); var response = controller.Fibinacci(10); Assert.IsType <OkObjectResult>(response); var value = ((OkObjectResult)response).Value; Assert.IsType <List <double> >(value); ((List <double>)value).Should().BeEquivalentTo(expected); }