public void Arrange() { var stubDataFile = new FileInfo(@"C:\SomeFile.txt"); _cancellationTokenSource = new CancellationTokenSource(); ConfigurationManager.AppSettings["DeclarationsEnabled"] = "both"; _pollingMessageReceiver = new Mock <IPollingMessageReceiver>(); _pollingMessageReceiver.Setup(x => x.ReceiveAsAsync <EmployerRefreshLevyQueueMessage>()). ReturnsAsync(new FileSystemMessage <EmployerRefreshLevyQueueMessage>(stubDataFile, stubDataFile, new EmployerRefreshLevyQueueMessage { PayeRef = ExpectedPayeRef })).Callback(() => { _cancellationTokenSource.Cancel(); }); _mediator = new Mock <IMediator>(); _mediator.Setup(x => x.SendAsync(It.IsAny <GetEnglishFractionUpdateRequiredRequest>())) .ReturnsAsync(new GetEnglishFractionUpdateRequiredResponse { UpdateRequired = false }); _mediator.Setup(x => x.SendAsync(It.IsAny <UpdateEnglishFractionsCommand>())).ReturnsAsync(Unit.Value); _logger = new Mock <ILog>(); _levyDeclaration = new LevyDeclaration(_pollingMessageReceiver.Object, _mediator.Object, _logger.Object); }