Merge pull request 'feat(tree): server-authoritative realtime tree updates' (#15) from feat/realtime-tree-server into develop

apps/client/src/features/page/tree/utils/utils.test.ts

@@ -0,0 +1,40 @@
+import { describe, it, expect } from "vitest";
+import { buildTree } from "./utils";
+import type { IPage } from "@/features/page/types/page.types.ts";
+
+function page(id: string, position: string): IPage {
+  return {
+    id,
+    slugId: `slug-${id}`,
+    title: id.toUpperCase(),
+    icon: "",
+    position,
+    hasChildren: false,
+    spaceId: "space-1",
+    parentPageId: null as unknown as string,
+  } as IPage;
+}
+
+describe("buildTree", () => {
+  it("builds one node per unique page", () => {
+    const tree = buildTree([page("a", "a1"), page("b", "a2")]);
+    expect(tree.map((n) => n.id)).toEqual(["a", "b"]);
+  });
+
+  it("dedups a duplicate id so the tree has no duplicate node", () => {
+    // A realtime cache write could append a page twice; buildTree must not emit
+    // two references to the same node (which would crash the sidebar render with
+    // a duplicate React key).
+    const tree = buildTree([
+      page("a", "a1"),
+      page("b", "a2"),
+      page("a", "a1"), // duplicate id
+    ]);
+
+    expect(tree).toHaveLength(2);
+    expect(tree.map((n) => n.id).sort()).toEqual(["a", "b"]);
+    // No id appears more than once.
+    const ids = tree.map((n) => n.id);
+    expect(new Set(ids).size).toBe(ids.length);
+  });
+});

apps/client/src/features/page/tree/utils/utils.ts

@@ -29,7 +29,14 @@ export function buildTree(pages: IPage[]): SpaceTreeNode[] {
     };
   });
 
+  // Defense-in-depth: a duplicate id in `pages` would push two references to the
+  // same node, producing a duplicate React key that crashes the sidebar render.
+  // Track ids we've already pushed and skip repeats so a stray duplicate from a
+  // realtime cache write can never break the tree.
+  const seen = new Set<string>();
   pages.forEach((page) => {
+    if (seen.has(page.id)) return;
+    seen.add(page.id);
     tree.push(pageMap[page.id]);
   });