at the end of initialization of all subclasses of VirtualContainerBase, the skin and its flow must be configured completely: in particular, the assertion below must be satisfied:

assertEquals(control.getItems().size(), flow.getCellCount());

TableViewSkin is the only one that fails this test (below are fixtures for all). Reason seems to be a missing updateItemCount in its constructor: comparing to the other, that method is called explicitly in ListViewSkin and implicitly for the tree/table/Skin in their setRoot(..).

    /**
     * bug in TableViewSkin: virtualFlow's cellCount not initialized.
     */
    @Test
    public void testTableSkinCellCountInitial() {
        TableView<Locale> control = new TableView<>(FXCollections.observableArrayList(Locale.getAvailableLocales()));
        control.setSkin(new TableViewSkin<>(control) {
            {
                assertEquals("flow's cellCount must be initialized", control.getItems().size(),
                        getVirtualFlow().getCellCount());
            }
        });
    }
    
    @Test
    public void testTreeTableSkinCellCountInitial() {
        List<TreeItem<Locale>> treeItems = Arrays.stream(Locale.getAvailableLocales())
                .map(TreeItem::new)
                .collect(Collectors.toList());
        TreeItem<Locale> root = new TreeItem<>(new Locale("dummy"));
        root.setExpanded(true);
        root.getChildren().addAll(treeItems);
        TreeTableView<Locale> control = new TreeTableView<>(root);
        control.setSkin(new TreeTableViewSkin<>(control) {
            {
                assertEquals("flow's cellCount must be initialized", treeItems.size() + 1,
                        getVirtualFlow().getCellCount());
            }
        });
    }
    
    @Test
    public void testTreeSkinCellCountInitial() {
        List<TreeItem<Locale>> treeItems = Arrays.stream(Locale.getAvailableLocales())
                .map(TreeItem::new)
                .collect(Collectors.toList());
        TreeItem<Locale> root = new TreeItem<>(new Locale("dummy"));
        root.setExpanded(true);
        root.getChildren().addAll(treeItems);
        TreeView<Locale> control = new TreeView<>(root);
        control.setSkin(new TreeViewSkin<>(control) {
            {
                assertEquals("flow's cellCount must be initialized", treeItems.size() +1,
                        getVirtualFlow().getCellCount());
            }
        });
    }
    
    @Test
    public void testListSkinCellCountInitial() {
        ListView<Locale> control = new ListView<>(FXCollections.observableArrayList(Locale.getAvailableLocales()));
        control.setSkin(new ListViewSkin<>(control) {
            {
                assertEquals("flow's cellCount must be initialized", control.getItems().size(),
                        getVirtualFlow().getCellCount());
            }
        });
    }