public void ListAsyncTest1()
        {
            var mock = new Mock <IUploadFileRepository>();

            mock.Setup(m => m.FindAllAsync(It.IsAny <Expression <Func <UploadFile, UploadFileViewModel> > >()))
            .Returns(Enumerable.Empty <UploadFileViewModel>().ToAsyncEnumerable());

            var service = new UploadFileService(mock.Object);
            var files   = service.ListAsync();

            Assert.Empty(files.ToEnumerable());
        }
        public async Task ListAsyncTest3()
        {
            var mock = new Mock <IUploadFileRepository>();

            mock.Setup(m => m.FindAllAsync(It.IsAny <Expression <Func <UploadFile, UploadFileViewModel> > >()))
            .Returns(Enumerable.Range(0, 10).Select(i => new UploadFileViewModel()
            {
                Id = i
            }).ToAsyncEnumerable());

            var service = new UploadFileService(mock.Object);
            var files   = service.ListAsync();

            Assert.Equal(10, await files.CountAsync());
        }