public void UnselectAll_Clears_SelectedIndex_And_SelectedItem() { var target = new TestSelector { Template = Template(), Items = new[] { "Foo", "Bar", "Baz" }, SelectionMode = SelectionMode.Multiple, SelectedIndex = 0, }; target.ApplyTemplate(); target.Presenter.ApplyTemplate(); target.UnselectAll(); Assert.Equal(-1, target.SelectedIndex); Assert.Equal(null, target.SelectedItem); }