it("retains a local section order when the initial cache lacks its entry", () => {
    const { orderAtom, queryClient, store } = createHarness();
    const localOrder = ["threads", "projects", "pinned"];
    store.set(orderAtom, localOrder);
    const response = serverResponse();
    response.preferences = Object.fromEntries(
      Object.entries(response.preferences).filter(([key]) => key !== "sidebar.sectionOrder"),
    ) as UiPreferencesResponse["preferences"];
    setCachedUiPreferences(queryClient, response);

    startUiPreferencesSync({ queryClient, store });

    expect(store.get(orderAtom)).toEqual(localOrder);
    expect(mocks.set).not.toHaveBeenCalled();
  });

  it("keeps edits local without an error notification when the server lacks the entry", async () => {
    const { orderAtom, queryClient, store } = createHarness();
    startUiPreferencesSync({ queryClient, store });
    const response = serverResponse();
    response.preferences = Object.fromEntries(
      Object.entries(response.preferences).filter(([key]) => key !== "sidebar.sectionOrder"),
    ) as UiPreferencesResponse["preferences"];
    setCachedUiPreferences(queryClient, response);

    store.set(orderAtom, ["threads"]);
    await waitForUiPreferenceWrites();

    expect(store.get(orderAtom)).toEqual(["threads"]);
    expect(mocks.set).not.toHaveBeenCalled();
    expect(mocks.toastError).not.toHaveBeenCalled();
    expect(hasPendingUiPreferenceWrite("sidebar.sectionOrder")).toBe(false);
  });

  it("records an acknowledged write after its cached entry disappears", async () => {
    const { orderAtom, queryClient, store } = createHarness();
    startUiPreferencesSync({ queryClient, store });
    setCachedUiPreferences(queryClient, serverResponse());
    const response = serverResponse();
    response.preferences = Object.fromEntries(
      Object.entries(response.preferences).filter(([key]) => key !== "sidebar.sectionOrder"),
    ) as UiPreferencesResponse["preferences"];
    mocks.set.mockImplementationOnce(async (input) => {
      setCachedUiPreferences(queryClient, response);
      return { key: input.key, revision: 1, value: input.value };
    });

    store.set(orderAtom, ["threads"]);
    await waitForUiPreferenceWrites();

    expect(getCachedUiPreferences(queryClient)?.preferences["sidebar.sectionOrder"])
      .toEqual({ revision: 1, value: ["threads"] });
    expect(mocks.toastError).not.toHaveBeenCalled();
    expect(store.get(orderAtom)).toEqual(["threads"]);
  });