HttpFileCollectionBase: Mocking Count-Property

I try to mock the Count-Property of an instance of HttpFileCollectionBase - but somehow it doesn't work.

var fakedRequest = new Mock<H开发者_开发问答ttpRequestBase>();
var fakedFile = new Mock<HttpPostedFileBase>();
fakedFile.SetupGet(x => x.InputStream).Returns(inputStream);
var fakedFileCollection = new Mock<HttpFileCollectionBase>();
fakedFileCollection.SetupGet(x => x.Count).Returns(1);
fakedRequest.SetupGet(x => x.Files).Returns(fakedFileCollection.Object);
fakedRequest.SetupGet(x => x.Files[0]).Returns(fakedFile.Object);

var sut = new TestableExploreController(null, fakedTemporaryStorageRepository.Object)
    {
         HttpRequest = fakedRequest.Object
    };

As you see, I create a mocked HttpRequest, which I inject to the system under test. The Count-Property is defined to return 1 - but it always returns 0. I'm using Moq.

What am I doing wrong?

Scott Hanselman blogged about this. The problem is the following line:

fakedRequest.SetupGet(x => x.Files[0]).Returns(fakedFile.Object);

Try like this and it should work:

var fakedRequest = new Mock<HttpRequestBase>();
var fakedFile = new Mock<HttpPostedFileBase>();
fakedFile.SetupGet(x => x.InputStream).Returns(inputStream);
var fakedFileCollection = new Mock<HttpFileCollectionBase>();
fakedFileCollection.SetupGet(x => x.Count).Returns(1);
fakedFileCollection.SetupGet(x => x[0]).Returns(fakedFile.Object);
fakedRequest.SetupGet(x => x.Files).Returns(fakedFileCollection.Object);

Here's a deeper example using NSubstitute that allows you to foreach over the file collection

var request = Substitute.For<HttpRequestBase>();

var firstFile = Substitute.For<HttpPostedFileBase>();
firstFile.ContentLength.Returns(1);
firstFile.FileName.Returns("firstFile.txt");
firstFile.ContentType.Returns("text");
firstFile.InputStream.Returns(new MemoryStream());

var secondFile = Substitute.For<HttpPostedFileBase>();
secondFile.ContentLength.Returns(1);
secondFile.FileName.Returns("secondFile.txt");
secondFile.ContentType.Returns("text");
secondFile.InputStream.Returns(new MemoryStream());

var fileKeys = new[] { "1", "2" };

var files = Substitute.For<HttpFileCollectionBase>();
files.GetEnumerator().Returns(fileKeys.GetEnumerator());

files[fileKeys[0]].Returns(firstFile);
files[fileKeys[1]].Returns(secondFile);

request.Files.Returns(files);

Example caller usage https://stackoverflow.com/a/1760523/37055