React Router Future Flag warning

[mshabarov]

Description of the bug

There's a number of warnings triggered by React Router when using the latest Vaadin Flow snapshot/pre-release (24.6):
⚠️ React Router Future Flag Warning: React Router will begin wrapping state updates in React.startTransition in v7. You can use the v7_startTransition future flag to opt-in early. For more information, see https://reactrouter.com/v6/upgrading/future#v7_starttransition. indexhtml-CdhAQHz9.js:51:6661
⚠️ React Router Future Flag Warning: Relative route resolution within Splat routes is changing in v7. You can use the v7_relativeSplatPath future flag to opt-in early. For more information, see https://reactrouter.com/v6/upgrading/future#v7_relativesplatpath. indexhtml-CdhAQHz9.js:51:6661
⚠️ React Router Future Flag Warning: The persistence behavior of fetchers is changing in v7. You can use the v7_fetcherPersist future flag to opt-in early. For more information, see https://reactrouter.com/v6/upgrading/future#v7_fetcherpersist. indexhtml-CdhAQHz9.js:51:6661
⚠️ React Router Future Flag Warning: Casing of formMethod fields is being normalized to uppercase in v7. You can use the v7_normalizeFormMethod future flag to opt-in early. For more information, see https://reactrouter.com/v6/upgrading/future#v7_normalizeformmethod. indexhtml-CdhAQHz9.js:51:6661
⚠️ React Router Future Flag Warning: RouterProvider hydration behavior is changing in v7. You can use the v7_partialHydration future flag to opt-in early. For more information, see https://reactrouter.com/v6/upgrading/future#v7_partialhydration. indexhtml-CdhAQHz9.js:51:6661
⚠️ React Router Future Flag Warning: The revalidation behavior after 4xx/5xx action responses is changing in v7. You can use the v7_skipActionErrorRevalidation future flag to opt-in early. For more information, see https://reactrouter.com/v6/upgrading/future#v7_skipactionerrorrevalidation.

Options:

• to opt-in these features, fix the behaviour that fails after that
• to opt-out from these features for now, this though will come back later.

Expected behavior

No warnings

Minimal reproducible example

Any Vaadin 24.6 and 24.5 application that uses React Router (by default).

Versions

• Vaadin / Flow version: 24.6 pre and 24.5.

[caalador]

There is an open proposal to have the possibility to silence the warning without opting in.
remix-run/react-router#12321

[mshabarov]

Adding all of these feature flags to the Flow-Hilla hybrid example looks promising, I couldn't spot any warning or unexpected behaviour:

// index.tsx:
function App() {
    return <AuthProvider>
        <RouterProvider router={router} future={{ v7_startTransition: true }} />
    </AuthProvider>;
}

// routes.tsx:
.build({
    future: {
        v7_fetcherPersist: true,
        v7_normalizeFormMethod: true,
        v7_partialHydration: true,
        v7_relativeSplatPath: true,
        v7_skipActionErrorRevalidation: true
    }
 });