public void GetFullPath_should_provide_rooted_path_when_relative_directory_is_Added() { string dotNetDir = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName); string[] files = { "fileA", "fileB" }; var pc = new PathCollection { FileSystem = new TestFileSystem(), }; pc.Add("relativeDirectory"); var path = pc.GetFullPath("fileB"); Assert.Equal("/working/relativeDirectory/fileB", path); }