I am currently unit testing a piece of code that should throw an exception when a file cannot be deleted.
Here’s the piece of code I am trying to test:

public void DeleteFile(string path)
{
    try
    {
        if (File.Exists(path))
        {
            File.Delete(path);
        }
    }
    catch (Exception e)
    {
        throw FileServiceException.BecauseCouldNotDeleteFile(e);
    }
}

The test case I originally created worked perfectly fine on Windows. But our CI/CD runs on Linux images.
Here’s the test case:

[Fact]
public void DeleteFile_Throws_ExceptionIfFileCannotBeDeleted()
{
    var filePath = $"{Path.GetTempPath()}{Guid.NewGuid()}.jpeg";
    using var file = File.Create(filePath);

    Assert.Throws<FileServiceException>(() =>_service.DeleteFile(filePath));

    // Make sure to delete file after the test
    _service.DeleteFile(filePath);
}

This is my current testcase. I’ve tried setting the UnixFileMode to None, and I’ve tried setting the FileAttributes to Hidden using: File.SetAttributes(filePath, FileAttributes.Hidden); but none of those seem to work.

[Fact]
public void DeleteFile_Throws_ExceptionIfFileCannotBeDeleted()
{
    var filePath = $"{Path.GetTempPath()}{Guid.NewGuid()}.jpeg";
    File.Create(filePath);
    File.SetUnixFileMode(filePath, UnixFileMode.None);


    Assert.Throws<IOException>(() =>_service.DeleteFile(filePath));

    // Make sure to delete file after the test
    _service.DeleteFile(filePath);
}