[Bug]: v7_partialHydration with lazy routes result in empty route

[lasseklovstad]

What version of React Router are you using?

6.21.0

Steps to Reproduce

1. Create a new router with RouterProvider
2. Add a lazy route
3. Add feature flag v7_partialHydration=true

let router = createBrowserRouter(
  [
    {
      path: '/',
      lazy: () => import('./test'),
    },
  ],
  { future: { v7_partialHydration: true } }
);

export default function App() {
  return <RouterProvider router={router} />;
}

// test.tsx
export const Component = () => {
  return <div>Hello, I am lazy</div>;
};

Reproduction:
https://stackblitz.com/edit/github-bzxwek?file=src%2Fapp.tsx

Expected Behavior

As of my understanding feature flags is the default behavior in the next version so I want to set this flag to true even though this feature (partial hydration) should only apply to server rendered apps?

Anyways, when setting this flag to true it is expected not to break lazy routes.

Actual Behavior

lazy route is not rendered and warning in console: Matched leaf route at location "/" does not have an element or Component. This means it will render an with a null value by default resulting in an "empty" page.

[brophdawg11]

I want to set this flag to true even though this feature (partial hydration) should only apply to server rendered apps

Yep! That's right - this is definitely a bug as lazy routes should work fine in SPA's with partialHydration specified. Also worth noting, if you previously had a fallbackElement, you'd want to move that to a HydrateFallback/hydrateFallbackElement on a root route (or deeper if you wish). HydrateFallback is basically a more powerful fallbackElement since it can be specified at any level of the tree.

[brophdawg11]

This is fixed in #11121 and will be available in the next release 👍

[github-actions]

🤖 Hello there,

We just published version 6.21.1-pre.0 which involves this issue. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!

[github-actions]

🤖 Hello there,

We just published version 6.21.1 which involves this issue. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!