Serialize toolbox writes and preserve concurrent edits

e2e/persistence.spec.js

@@ -0,0 +1,29 @@
+// Rôle : vérifie l'atomicité des snapshots avec une vraie transaction IndexedDB.
+import { test, expect } from "@playwright/test";
+import { resetSokkoStorage } from "./helpers/storage.js";
+
+test("a synchronous snapshot error aborts all its IndexedDB writes", async ({ page }) => {
+  await resetSokkoStorage(page);
+  const result = await page.evaluate(async () => {
+    const db = await import("/src/utils/indexedDbStorage.js");
+    await db.setToolboxSnapshot([{ id: "saved", modules: [] }], { game: "saved" }, { "saved:note": { text: "Keep" } });
+    let errorName = "";
+    try {
+      await db.setToolboxSnapshot([{ id: "broken" }], {}, { "broken:note": { invalid: () => {} } });
+    } catch (error) {
+      errorName = error.name;
+    }
+    return {
+      errorName,
+      toolboxes: await db.getToolboxes(),
+      links: await db.getLinks(),
+      modules: await db.getAllModuleData()
+    };
+  });
+  expect(result).toEqual({
+    errorName: "DataCloneError",
+    toolboxes: [{ id: "saved", modules: [] }],
+    links: { game: "saved" },
+    modules: [{ key: "saved:note", data: { text: "Keep" } }]
+  });
+});