feat(homepage): synchronize canvas layouts across devices (#1515)

plugins/homepage/tests/backend/layout-sync.test.ts

@@ -0,0 +1,84 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { startServer, type TestServer } from "./helpers.js";
+
+let server: TestServer | undefined;
+afterEach(async () => {
+  await server?.close();
+  server = undefined;
+});
+
+describe("homepage layout sync", () => {
+  it("maps widget ids across devices and keeps canvas geometry", async () => {
+    server = await startServer();
+    const items = server.mock.syncEntities.find(
+      (entry) => entry.type === "homepageItems",
+    )!;
+    const entity = server.mock.syncEntities.find(
+      (entry) => entry.type === "homepageLayouts",
+    )!;
+    expect(entity.singleton).toBe(true);
+    expect(entity.order).toBeGreaterThan(items.order!);
+    const layout = {
+      entries: [{ itemId: 7, x: 10, y: 20, w: 300, h: 200, zOrder: 2 }],
+      pan: { x: 5, y: -3 },
+      zoom: 0.75,
+    };
+    const exported = await entity.serialize!(
+      { layout: JSON.stringify(layout) },
+      async (type, id) =>
+        type === "homepageItems" && id === 7 ? "widget-sync-id" : null,
+    );
+    expect(JSON.parse(exported.layout as string).entries[0].itemId).toBe(
+      "widget-sync-id",
+    );
+    const imported = await entity.deserialize!(exported, async (type, id) =>
+      type === "homepageItems" && id === "widget-sync-id" ? 91 : null,
+    );
+    expect(JSON.parse(imported.layout as string)).toEqual({
+      ...layout,
+      entries: [{ ...layout.entries[0], itemId: 91 }],
+    });
+  });
+
+  it("drops unavailable widgets and refuses numeric wire ids", async () => {
+    server = await startServer();
+    const entity = server.mock.syncEntities.find(
+      (entry) => entry.type === "homepageLayouts",
+    )!;
+    const resolveId = vi.fn(async () => null);
+    const result = await entity.deserialize!(
+      {
+        layout: JSON.stringify({
+          entries: [
+            { itemId: "deleted", x: 1 },
+            { itemId: 7, x: 2 },
+          ],
+          zoom: 1,
+        }),
+      },
+      resolveId,
+    );
+    expect(JSON.parse(result.layout as string)).toEqual({
+      entries: [],
+      zoom: 1,
+    });
+    expect(resolveId).toHaveBeenCalledExactlyOnceWith(
+      "homepageItems",
+      "deleted",
+    );
+  });
+
+  it("keeps an empty layout and rejects malformed JSON instead of copying local ids", async () => {
+    server = await startServer();
+    const entity = server.mock.syncEntities.find(
+      (entry) => entry.type === "homepageLayouts",
+    )!;
+    const resolve = vi.fn(async () => null);
+    await expect(entity.serialize!({ layout: "{}" }, resolve)).resolves.toEqual(
+      { layout: "{}" },
+    );
+    await expect(
+      entity.serialize!({ layout: "broken" }, resolve),
+    ).rejects.toThrow();
+  });
+});