public void AllTagsAsJson_Should_Return_Model_And_Tags() { // Arrange Page page1 = AddDummyPage1(); page1.Tags = "a-tag,b-tag"; Page page2 = AddDummyPage2(); page2.Tags = "z-tag,a-tag"; // Act ActionResult result = _pagesController.AllTagsAsJson(); // Assert Assert.That(result, Is.TypeOf <JsonResult>(), "JsonResult"); JsonResult jsonResult = result as JsonResult; Assert.NotNull(jsonResult, "Null jsonResult"); var xxx = jsonResult.Data.GetType(); Assert.That(jsonResult.JsonRequestBehavior, Is.EqualTo(JsonRequestBehavior.AllowGet)); Assert.That(jsonResult.Data, Is.AssignableTo <IEnumerable <string> >()); _pageServiceMock.Verify(x => x.AllTags()); }