public void CategoriesForSelectDialog_should_return_JsonResult_when_invoked() { service.Setup(x => x.List()).Returns(Fakes.FakeCategoryList()).Verifiable(); service.Setup(x => x.ListCategoriesForProduct(It.IsAny <Guid>())).Returns(Fakes.FakeCategoryList()) .Verifiable(); var action = controller._CategoriesForSelectDialog(Guid.NewGuid()); Assert.That(action, Is.Not.Null); Assert.That(action, Is.InstanceOf <JsonResult>()); service.VerifyAll(); }