> For AI agents: the complete documentation index is available at https://wallarm.github.io/design-system/llms.txt, the full documentation bundle is available at https://wallarm.github.io/design-system/llms-full.txt.

# Migrating to v4

v4.0.0 removes one module: **TreeBase**.

**Codemod:** `tree-base-removed`, run by `migrator --from 3.x.y` (see [Migration guides](https://wallarm.github.io/design-system/get-started/migrations/index.md)).
It only reports: it changes no code.

## TreeBase is removed

TreeBase was a thin styled wrapper around Ark UI's tree view. It was never exported from the
package root, only from the `@wallarm-org/design-system/TreeBase` subpath, and that subpath no
longer exists. The removed names:

- the components `TreeBaseRoot`, `TreeBaseTree`, `TreeBaseLabel`, `TreeBaseItem`,
  `TreeBaseItemText`, `TreeBaseBranch`, `TreeBaseBranchControl`, `TreeBaseBranchText`,
  `TreeBaseBranchIndicator`, `TreeBaseBranchTrigger`, `TreeBaseBranchContent`,
  `TreeBaseBranchIndentGuide`, `TreeBaseNodeProvider`, `TreeBaseContext`, and the type
  `TreeBaseRootProps`;
- the Ark UI re-exports `createTreeCollection`, `TreeCollection`, `TreeNode` and
  `TreeViewExpandedChangeDetails`. If you still need them, import them from
  `@ark-ui/react/tree-view` and add `@ark-ui/react` to your own dependencies.

Rebuild the tree with [TreeView](https://wallarm.github.io/design-system/components/tree-view.md) (selectable rows) or
[Tree](https://wallarm.github.io/design-system/components/tree.md). Both take nested children instead of a collection:

```tsx
// Before
import { createTreeCollection, TreeBaseRoot, TreeBaseTree } from '@wallarm-org/design-system/TreeBase';

// After
import { TreeView, TreeViewItem } from '@wallarm-org/design-system/TreeView';

export const Files = () => (
  <TreeView>
    <TreeViewItem defaultOpen>
      Components
      <TreeViewItem>Button.tsx</TreeViewItem>
    </TreeViewItem>
  </TreeView>
);
```

The codemod marks every import from `@wallarm-org/design-system/TreeBase` (named, aliased,
namespace and type-only) and lists it in `wds-migration.md`. Imports of `Tree`, `TreeView` and a
local `./TreeBase` are left alone.