public void TestGetParentFolder() { //Arrange var parent = new Folder() { ID = 6, Name = "Folder6", IsRoot = true, SubFolders = new List <Folder>(), Files = new List <File>() }; var child = new Folder() { ID = 7, Name = "Folder7", ParentID = 6, Parent = parent, IsRoot = false, SubFolders = new List <Folder>(), Files = new List <File>() }; //Act parent.SubFolders.Add(child); _folder.AddFolder(parent); _folder.AddFolder(child); //Assert Assert.AreEqual(parent, _folder.GetParentFolder(child)); }