How to unit test IStorageFile?

[daniel-lerch]

I am using Avalonia's IStorageProvider and its related APIs like IStorageFile. Instead of passing a path to my I/O services, I pass an IStorageFile. This works perfectly for application code. However, I have no idea how to get an IStorageFile for given path for a unit test. In the documentation about StorageProvider and Storage Items I could not find any hints.

[maxkatz6]

Typically, you would use StorageProvider.TryGetFileFromPathAsync in normal apps, when you want to get a file from a random string path.
With unit tests we don't have a simpler API, but you can use these anyway, if you are running headless tests.

[cedric56]

You can mock using moq

var file = new Mock<IStorageFile>();
file.Setup(f => f.Path).Returns(new System.Uri(@"C:/foo.txt"));

var provider = new Mock<IStorageProvider>();
provider.Setup(x => x.OpenFilePickerAsync(It.IsAny<FilePickerOpenOptions>())).ReturnsAsync([file.Object]);
provider.Setup(x => x.CanOpen).Returns(true);
var services = new ServiceCollection();
services.AddSingleton(provider.Object);
Ioc.Default.ConfigureServices(services.BuildServiceProvider());