public async void HttpGet_DownloadProducerAmendmentsCsv_ShouldReturnFileContentType() { // Arrange BreadcrumbService breadcrumb = A.Dummy<BreadcrumbService>(); ISearcher<ProducerSearchResult> producerSearcher = A.Dummy<ISearcher<ProducerSearchResult>>(); IWeeeClient weeeClient = A.Fake<IWeeeClient>(); CSVFileData csvData = A.Dummy<CSVFileData>(); A.CallTo(() => weeeClient.SendAsync(A<string>._, A<GetProducerAmendmentsHistoryCSV>._)) .Returns(new CSVFileData { FileName = "test.csv", FileContent = "123,abc" }); Func<IWeeeClient> weeeClientFunc = A.Fake<Func<IWeeeClient>>(); A.CallTo(() => weeeClientFunc()) .Returns(weeeClient); ProducersController controller = new ProducersController(breadcrumb, producerSearcher, weeeClientFunc, cache); //Act var result = await controller.DownloadProducerAmendmentsCsv("WEE/AA1111AA"); //Assert Assert.IsType<FileContentResult>(result); }