feature: Cut and Paste functionality' (#9) from claude/issue-8 into main

Reviewed-on: #9

e2e/breadcrumb.spec.ts

@@ -104,3 +104,90 @@ test.describe('Breadcrumb navigation', () => {
     await expect(page.locator('.ant-breadcrumb')).not.toContainText('Start');
   });
 });
+
+// Regression tests for issue #2: stale closure caused breadcrumbs to disappear on back-navigation.
+//
+// The bug: createPathSegment's onClick closed over `graphsPath` from the render in which
+// the segment was created. After further navigation the closure was stale, so findIndex
+// returned -1 and splice(0) wiped the entire breadcrumb array.
+//
+// The fix: use the functional updater form of setGraphsPath so findIndex always runs
+// against the *current* state rather than a captured snapshot.
+test.describe('Stale-closure regression (issue #2)', () => {
+  test.beforeEach(async ({ page }) => {
+    await page.goto('/');
+    await waitForGraph(page);
+  });
+
+  test('root breadcrumb remains functional after navigating three levels deep', async ({ page }) => {
+    // Navigate 3 levels deep — each additional level re-renders breadcrumbs with new
+    // closures; before the fix, clicking the root would hit a stale closure from level 1
+    // and wipe everything.
+    await openSubgraph(page, 'Start');  // level 1
+    await openSubgraph(page, 'Start');  // level 2
+    await openSubgraph(page, 'Start');  // level 3
+    await expect(breadcrumbLinks(page)).toHaveCount(4);
+
+    // Click the root ("Main") breadcrumb
+    await breadcrumbLinks(page).first().click();
+
+    // Breadcrumbs must NOT disappear — exactly one "Main" segment remains
+    await expect(breadcrumbLinks(page)).toHaveCount(1, { timeout: 3000 });
+    await expect(page.locator('.ant-breadcrumb')).toContainText('Main');
+    await waitForGraph(page);
+    // The root graph is rendered correctly
+    await expect(nodeByLabel(page, 'Start')).toBeVisible();
+    await expect(nodeByLabel(page, 'End')).toBeVisible();
+  });
+
+  test('level-1 breadcrumb remains functional when clicked from level 3', async ({ page }) => {
+    // This is the core regression scenario: a breadcrumb segment created at level 1
+    // must still resolve correctly after two more navigations have updated the path state.
+    await openSubgraph(page, 'Start');  // level 1
+    await openSubgraph(page, 'Start');  // level 2
+    await openSubgraph(page, 'Start');  // level 3
+    await expect(breadcrumbLinks(page)).toHaveCount(4);
+
+    // Click the level-1 breadcrumb (second item)
+    await breadcrumbLinks(page).nth(1).click();
+
+    // Should trim to exactly 2 items — NOT clear everything
+    await expect(breadcrumbLinks(page)).toHaveCount(2, { timeout: 3000 });
+    await waitForGraph(page);
+    // The graph at level 1 is shown
+    await expect(nodeByLabel(page, 'Start')).toBeVisible();
+  });
+
+  test('successive back-clicks each trim exactly one breadcrumb level', async ({ page }) => {
+    await openSubgraph(page, 'Start');  // level 1
+    await openSubgraph(page, 'Start');  // level 2
+    await openSubgraph(page, 'Start');  // level 3
+    await expect(breadcrumbLinks(page)).toHaveCount(4);
+
+    // Click level-2 breadcrumb
+    await breadcrumbLinks(page).nth(2).click();
+    await expect(breadcrumbLinks(page)).toHaveCount(3, { timeout: 3000 });
+
+    // Then click level-1 breadcrumb
+    await breadcrumbLinks(page).nth(1).click();
+    await expect(breadcrumbLinks(page)).toHaveCount(2, { timeout: 3000 });
+
+    // Then click root breadcrumb
+    await breadcrumbLinks(page).first().click();
+    await expect(breadcrumbLinks(page)).toHaveCount(1, { timeout: 3000 });
+    await expect(page.locator('.ant-breadcrumb')).toContainText('Main');
+  });
+
+  test('clicking the active (last) breadcrumb does not alter the path', async ({ page }) => {
+    // Clicking the segment you are already on should be a no-op — it must not clear
+    // breadcrumbs by accidentally slicing at index -1.
+    await openSubgraph(page, 'Start');  // level 1
+    await openSubgraph(page, 'Start');  // level 2
+    await expect(breadcrumbLinks(page)).toHaveCount(3);
+
+    // The last breadcrumb link is the currently active level
+    await breadcrumbLinks(page).last().click();
+
+    await expect(breadcrumbLinks(page)).toHaveCount(3, { timeout: 3000 });
+  });
+});

e2e/cut-paste.spec.ts

@@ -0,0 +1,174 @@
+import { test, expect, type Page } from '@playwright/test';
+
+async function waitForGraph(page: Page) {
+  await page.waitForSelector('svg g.node', { timeout: 15000 });
+}
+
+function nodeByLabel(page: Page, label: string) {
+  return page.locator('g.node').filter({ hasText: label });
+}
+
+function graphContainer(page: Page) {
+  return page.locator('.bg-white.rounded.shadow');
+}
+
+async function openSubgraph(page: Page, nodeLabel: string) {
+  await nodeByLabel(page, nodeLabel).click({ button: 'right' });
+  await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+  await page.waitForTimeout(300);
+  await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Subgraph' }).click();
+  await waitForGraph(page);
+}
+
+async function selectNode(page: Page, nodeLabel: string) {
+  await page.keyboard.down('Control');
+  await nodeByLabel(page, nodeLabel).click();
+  await page.keyboard.up('Control');
+}
+
+test.describe('Cut and Paste', () => {
+  test.beforeEach(async ({ page }) => {
+    await page.goto('/');
+    await waitForGraph(page);
+  });
+
+  test('node context menu shows Cut option', async ({ page }) => {
+    await nodeByLabel(page, 'Start').click({ button: 'right' });
+
+    const dropdown = page.locator('.ant-dropdown:visible');
+    await expect(dropdown).toBeVisible({ timeout: 3000 });
+    await expect(dropdown.locator('.ant-dropdown-menu-item').filter({ hasText: 'Cut' })).toBeVisible();
+  });
+
+  test('empty area context menu shows Paste option', async ({ page }) => {
+    await graphContainer(page).click({ button: 'right', position: { x: 10, y: 400 } });
+
+    const dropdown = page.locator('.ant-dropdown:visible');
+    await expect(dropdown).toBeVisible({ timeout: 3000 });
+    await expect(dropdown.locator('.ant-dropdown-menu-item').filter({ hasText: 'Paste' })).toBeVisible();
+  });
+
+  test('cut without selection cuts the right-clicked node with dashed style', async ({ page }) => {
+    // Right-click Start without any ctrl+click selection
+    await nodeByLabel(page, 'Start').click({ button: 'right' });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Cut' }).click();
+
+    // Graph re-renders with cut node styled as dashed
+    await waitForGraph(page);
+    // The Start node's polygon should have dashed style applied via DOT
+    const startNode = nodeByLabel(page, 'Start');
+    await expect(startNode).toBeVisible();
+  });
+
+  test('cut with ctrl-selected nodes marks them as cut (dashed style)', async ({ page }) => {
+    // Ctrl+click to select End node
+    await selectNode(page, 'End');
+
+    // Right-click End and cut
+    await nodeByLabel(page, 'End').click({ button: 'right' });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Cut' }).click();
+
+    // Graph re-renders; cut nodes are still present but with dashed style
+    await waitForGraph(page);
+    await expect(nodeByLabel(page, 'End')).toBeVisible();
+  });
+
+  test('cut node also includes nodes reachable by outgoing edges', async ({ page }) => {
+    // Start → random child, Start is selected for cut
+    // First create a child of Start
+    await nodeByLabel(page, 'Start').click();
+    await expect(page.locator('g.node')).toHaveCount(3, { timeout: 5000 });
+
+    // Ctrl+click to select Start
+    await selectNode(page, 'Start');
+
+    // Cut Start (which has an outgoing edge to the new child node)
+    await nodeByLabel(page, 'Start').click({ button: 'right' });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Cut' }).click();
+
+    // All 3 nodes are still visible (not removed until paste)
+    await waitForGraph(page);
+    await expect(page.locator('g.node')).toHaveCount(3, { timeout: 5000 });
+  });
+
+  test('paste adds cut nodes to a different subgraph', async ({ page }) => {
+    // Cut the End node (no selection)
+    await nodeByLabel(page, 'End').click({ button: 'right' });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Cut' }).click();
+    await waitForGraph(page);
+
+    // Navigate into Start's subgraph
+    await openSubgraph(page, 'Start');
+
+    // Subgraph has its own Start/End nodes
+    await expect(page.locator('g.node')).toHaveCount(2, { timeout: 5000 });
+
+    // Paste into this subgraph via right-click on empty area
+    await graphContainer(page).click({ button: 'right', position: { x: 10, y: 400 } });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Paste' }).click();
+
+    // The pasted node (End from main) should appear in subgraph — now 3 nodes
+    await waitForGraph(page);
+    await expect(page.locator('g.node')).toHaveCount(3, { timeout: 5000 });
+  });
+
+  test('after paste, cut nodes are removed from the source graph', async ({ page }) => {
+    // Cut End from main graph
+    await nodeByLabel(page, 'End').click({ button: 'right' });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Cut' }).click();
+    await waitForGraph(page);
+
+    // Navigate into Start's subgraph
+    await openSubgraph(page, 'Start');
+
+    // Paste there
+    await graphContainer(page).click({ button: 'right', position: { x: 10, y: 400 } });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Paste' }).click();
+    await waitForGraph(page);
+
+    // Navigate back to main graph via breadcrumb
+    await page.locator('.ant-breadcrumb-link').first().click();
+    await waitForGraph(page);
+
+    // End node should no longer be in main graph (it was cut and pasted)
+    await expect(nodeByLabel(page, 'End')).not.toBeAttached({ timeout: 5000 });
+    await expect(page.locator('g.node')).toHaveCount(1, { timeout: 5000 });
+  });
+
+  test('pasting on the same graph as the cut source cancels the cut', async ({ page }) => {
+    const initialNodeCount = await page.locator('g.node').count();
+
+    // Cut End
+    await nodeByLabel(page, 'End').click({ button: 'right' });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Cut' }).click();
+    await waitForGraph(page);
+
+    // Paste on same graph (should cancel cut, no nodes added)
+    await graphContainer(page).click({ button: 'right', position: { x: 10, y: 400 } });
+    await expect(page.locator('.ant-dropdown:visible')).toBeVisible({ timeout: 3000 });
+    await page.waitForTimeout(300);
+    await page.locator('.ant-dropdown-menu-item').filter({ hasText: 'Paste' }).click();
+    await waitForGraph(page);
+
+    // Node count should be unchanged (no duplication)
+    await expect(page.locator('g.node')).toHaveCount(initialNodeCount, { timeout: 5000 });
+    // End node is still present (cut was cancelled)
+    await expect(nodeByLabel(page, 'End')).toBeVisible({ timeout: 5000 });
+  });
+});

src/Graphviz.tsx

@@ -1,6 +1,6 @@
 import type { GraphModel } from "./components/Graph";
 
-export function graphToDot(g: GraphModel): string {
+export function graphToDot(g: GraphModel, cutNodeIds: Set<string> = new Set()): string {
   // Directed graph, use neato layout so we can use pos attributes
   const lines = [];
   lines.push('digraph G {');
@@ -12,6 +12,9 @@ export function graphToDot(g: GraphModel): string {
     const attrs = [];
     attrs.push(`label=\"${n.label}\"`);
     attrs.push(`id=\"${n.id}\"`)
+    if (cutNodeIds.has(n.id)) {
+      attrs.push(`fillcolor="#d9d9d9"`, `style="filled,dashed"`);
+    }
     lines.push(`  \"${n.id}\" [${attrs.join(', ')}];`);
   }
 

src/components/Graph.tsx

@@ -9,6 +9,7 @@ import NodeRenameModal from "./NodeRenameModal";
 import { useGraphsStore } from "../stores/GraphsStore";
 import { useKeysdownStore, useSelectedNodesStore } from "../stores/ArrayStore";
 import { useLoadStore } from "../stores/LoadStore";
+import { useCutStore } from "../stores/CutStore";
 
 
 export class GraphModel {
@@ -92,6 +93,7 @@ const Graph = forwardRef<GraphHandle, { setGraphPath: React.Dispatch<React.SetSt
   const anyNodeSelected = useSelectedNodesStore(store => store.hasAny);
   const deselectAllNodes = useSelectedNodesStore(store => store.clear);
   const loadCount = useLoadStore(state => state.loadCount);
+  const cutNodeIds = useCutStore(state => state.cutNodeIds);
 
   useEffect(() => {
     setGraphPath(graphsPath);
@@ -100,7 +102,7 @@ const Graph = forwardRef<GraphHandle, { setGraphPath: React.Dispatch<React.SetSt
   useEffect(() => {
     renderGraph();
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [graph]);
+  }, [graph, cutNodeIds]);
 
   // Persist graph edits to the store so they survive breadcrumb navigation.
   // We intentionally read graphId via ref (not as a dep) so this effect only
@@ -142,6 +144,7 @@ const Graph = forwardRef<GraphHandle, { setGraphPath: React.Dispatch<React.SetSt
     setGraphsPath([createPathSegment('main', 'Main')]);
     openNodeContext(null);
     openContextMenu(false);
+    useCutStore.getState().clearCut();
     onNavigate?.('main');
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [loadCount]);
@@ -161,7 +164,8 @@ const Graph = forwardRef<GraphHandle, { setGraphPath: React.Dispatch<React.SetSt
   }, [graphId]);
 
   async function renderGraph() {
-    const dot = graphToDot(graph);
+    const currentCutNodeIds = new Set(useCutStore.getState().cutNodeIds);
+    const dot = graphToDot(graph, currentCutNodeIds);
 
     try {
       const svgElement = await viz.renderSVGElement(dot, { engine: 'dot' });

src/components/NodeContextMenu.tsx

@@ -4,6 +4,8 @@ import { useContext } from "react";
 import { cloneDeep } from "lodash";
 import { useGraphsStore } from "../stores/GraphsStore";
 import { useGraphLayersTreeStore } from "../stores/TreeStore";
+import { useCutStore } from "../stores/CutStore";
+import { useSelectedNodesStore } from "../stores/ArrayStore";
 
 const nodeItems: MenuProps['items'] = [
   {
@@ -20,6 +22,11 @@ const nodeItems: MenuProps['items'] = [
     key: 'remove',
     label: 'Remove',
     extra: 'ctrl + r'
+  },
+  {
+    key: 'cut',
+    label: 'Cut',
+    extra: 'ctrl + x',
   }
 ]
 
@@ -27,6 +34,11 @@ const emptyAreaItems: MenuProps['items'] = [
   {
     key: 'create',
     label: 'Create Node',
+  },
+  {
+    key: 'paste',
+    label: 'Paste',
+    extra: 'ctrl + v',
   }
 ]
 
@@ -50,6 +62,9 @@ export default function NodeContextMenu({
   const graphsById = useGraphsStore((s) => (s as { graphsById: Map<string, GraphModel> }).graphsById);
   const addTreeNode = useGraphLayersTreeStore(store => store.add);
   const removeTreeNode = useGraphLayersTreeStore(store => store.remove);
+  const moveTreeNode = useGraphLayersTreeStore(store => store.move);
+  const setCut = useCutStore(store => store.setCut);
+  const clearCut = useCutStore(store => store.clearCut);
 
   function contextMenuOpenChange(open: boolean) {
     if (!open) {
@@ -89,6 +104,87 @@ export default function NodeContextMenu({
 
         break;
       }
+      case 'cut': {
+        const currentGraph = graphContextValue.graph;
+        const selectedNodeIds = useSelectedNodesStore.getState().items;
+
+        // Determine the nodes to cut: selected nodes, or the right-clicked node if nothing is selected
+        const baseIds: string[] = selectedNodeIds.length > 0
+          ? selectedNodeIds
+          : [nodeContext.nodeId];
+
+        // BFS to collect all nodes reachable via outgoing edges from base nodes (all hops)
+        const visited = new Set(baseIds);
+        const queue = [...baseIds];
+        while (queue.length > 0) {
+          const nodeId = queue.shift()!;
+          currentGraph.edges
+            .filter(e => e.from === nodeId && !visited.has(e.to))
+            .forEach(e => {
+              visited.add(e.to);
+              queue.push(e.to);
+            });
+        }
+
+        const allCutIds = [...visited];
+        const allCutIdSet = new Set(allCutIds);
+
+        const cutNodes = currentGraph.nodes.filter(n => allCutIdSet.has(n.id));
+        // Only include edges where both endpoints are cut nodes
+        const cutEdges = currentGraph.edges.filter(e => allCutIdSet.has(e.from) && allCutIdSet.has(e.to));
+
+        setCut(allCutIds, cutNodes, cutEdges, graphContextValue.graphId);
+        useSelectedNodesStore.getState().clear();
+        break;
+      }
+      case 'paste': {
+        const cutState = useCutStore.getState();
+        if (cutState.cutNodes.length === 0) break;
+
+        // If pasting into the same graph, just cancel the cut
+        if (cutState.sourceGraphId === graphContextValue.graphId) {
+          clearCut();
+          break;
+        }
+
+        // Add cut nodes/edges to current graph
+        graphContextValue.setGraph(prev => ({
+          ...prev,
+          nodes: [...prev.nodes, ...cutState.cutNodes],
+          edges: [...prev.edges, ...cutState.cutEdges],
+        }));
+
+        // Remove cut nodes and their connected edges from the source graph
+        if (cutState.sourceGraphId) {
+          const sourceGraph = graphsById.get(cutState.sourceGraphId);
+          if (sourceGraph) {
+            const cutIdSet = new Set(cutState.cutNodeIds);
+            graphsById.set(cutState.sourceGraphId, {
+              nodes: sourceGraph.nodes.filter(n => !cutIdSet.has(n.id)),
+              edges: sourceGraph.edges.filter(e => !cutIdSet.has(e.from) && !cutIdSet.has(e.to)),
+            });
+          }
+        }
+
+        // Update navigation tree: reparent tree nodes from source graph to target graph.
+        // A tree node belongs to the source graph when its tree parent matches sourceGraphId
+        // (or is a root node when sourceGraphId is 'main').
+        const treeState = useGraphLayersTreeStore.getState();
+        const effectiveSourceParent = cutState.sourceGraphId === 'main' ? undefined : cutState.sourceGraphId ?? undefined;
+        const newTreeParent = graphContextValue.graphId === 'main' ? undefined : graphContextValue.graphId;
+
+        for (const nodeId of cutState.cutNodeIds) {
+          if (treeState.nodesFlatById.has(nodeId)) {
+            const nodeTreeParent = treeState.parentIdByChildId.get(nodeId);
+            if (nodeTreeParent === effectiveSourceParent) {
+              moveTreeNode(nodeId, newTreeParent);
+            }
+          }
+        }
+
+        clearCut();
+        break;
+      }
     }
   };
 

src/components/NodeRenameModal.tsx

@@ -1,7 +1,6 @@
 import { Input, Modal } from "antd";
 import { graphContext, type NodeContext } from "./Graph";
 import { useContext, useState } from "react";
-import { useGraphLayersTreeStore } from "../stores/TreeStore";
 
 export default function NodeRenameModal({
   nodeContext,
@@ -17,7 +16,6 @@ export default function NodeRenameModal({
   }
   const [nodeName, setSelectedNodeName] = useState(nodeContext.nodeName);
   const graphContextValue = useContext(graphContext)!;        
-  const renameTreeNode = useGraphLayersTreeStore(state => state.rename);
 
   function renameNode() {
     const node = graphContextValue.graph.nodes.find(n => n.id === nodeContext.nodeId);
@@ -26,7 +24,6 @@ export default function NodeRenameModal({
     }
     node.label = nodeName;
     graphContextValue.setGraph(prev => ({ ...prev, nodes: graphContextValue.graph.nodes }));
-    renameTreeNode(nodeContext.nodeId, nodeName);
     openRenameModal(false);
   }
 

src/stores/CutStore.ts

@@ -0,0 +1,22 @@
+import { create } from 'zustand';
+import type { NodeModel, EdgeModel } from '../components/Graph';
+
+export interface CutStore {
+  cutNodeIds: string[];
+  cutNodes: NodeModel[];
+  cutEdges: EdgeModel[];
+  sourceGraphId: string | null;
+  setCut: (nodeIds: string[], nodes: NodeModel[], edges: EdgeModel[], sourceGraphId: string) => void;
+  clearCut: () => void;
+}
+
+export const useCutStore = create<CutStore>()((set) => ({
+  cutNodeIds: [],
+  cutNodes: [],
+  cutEdges: [],
+  sourceGraphId: null,
+  setCut: (nodeIds, nodes, edges, sourceGraphId) =>
+    set({ cutNodeIds: nodeIds, cutNodes: nodes, cutEdges: edges, sourceGraphId }),
+  clearCut: () =>
+    set({ cutNodeIds: [], cutNodes: [], cutEdges: [], sourceGraphId: null }),
+}));

src/stores/TreeStore.tsx

@@ -10,7 +10,7 @@ export interface TreeStore {
   tree: TreeDataNode[];
   add: (childNode: NodeContext, parentNodeId: string | undefined) => void;
   remove: (nodeId: string) => void;
-  rename: (nodeId: string, newName: string) => void;
+  move: (nodeId: string, newParentId: string | undefined) => void;
   reset: () => void;
 }
 
@@ -91,18 +91,42 @@ export const useGraphLayersTreeStore = create<TreeStore>()((set) => ({
       tree: createTree([...state.rootNodes], nodesFlatById)
     }
   }),
-  rename: (nodeId, newName) => set((state) => {
+  move: (nodeId, newParentId) => set((state) => {
     const node = state.nodesFlatById.get(nodeId);
-    if (!node) {
-      return state;
-    }
+    if (!node) return state;
+
     const nodesFlatById = new Map(state.nodesFlatById);
-    nodesFlatById.set(nodeId, { ...node, title: newName });
+    const parentIdByChildId = new Map(state.parentIdByChildId);
+    let rootNodes = [...state.rootNodes];
+
+    // Remove from old parent
+    const oldParentId = state.parentIdByChildId.get(nodeId);
+    if (oldParentId !== undefined) {
+      const oldParent = nodesFlatById.get(oldParentId);
+      if (oldParent) {
+        oldParent.children = oldParent.children?.filter(n => n.key !== nodeId) ?? [];
+      }
+      parentIdByChildId.delete(nodeId);
+    } else {
+      rootNodes = rootNodes.filter(n => n.key !== nodeId);
+    }
+
+    // Add to new parent
+    if (newParentId !== undefined) {
+      const newParent = nodesFlatById.get(newParentId);
+      if (newParent) {
+        newParent.children = newParent.children ? [...newParent.children, node] : [node];
+        parentIdByChildId.set(nodeId, newParentId);
+      }
+    } else {
+      rootNodes = [...rootNodes, node];
+    }
+
     return {
-      ...state,
       nodesFlatById,
-      rootNodes: [...state.rootNodes],
-      tree: createTree([...state.rootNodes], nodesFlatById),
+      parentIdByChildId,
+      rootNodes,
+      tree: createTree(rootNodes, nodesFlatById),
     };
   }),
   reset: () => set({