handling of redirects encountered in serverLoader changes with Single Fetch

[rossipedia]

Reproduction

https://github.com/rossipedia/await-single-fetch-shenanigans

https://stackblitz.com/~/rossipedia/await-single-fetch-shenanigans

System Info

System:
    OS: macOS 15.1
    CPU: (12) arm64 Apple M2 Max
    Memory: 26.83 GB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.11.0 - ~/.local/state/fnm_multishells/43462_1731267897329/bin/node
    Yarn: 1.22.22 - ~/.local/state/fnm_multishells/43462_1731267897329/bin/yarn
    npm: 10.9.0 - ~/.local/state/fnm_multishells/43462_1731267897329/bin/npm
    pnpm: 9.12.0 - ~/.local/state/fnm_multishells/43462_1731267897329/bin/pnpm
    bun: 1.0.2 - ~/.bun/bin/bun
  Browsers:
    Brave Browser: 111.1.49.132
    Chrome: 130.0.6723.117
    Edge: 130.0.2849.80
    Safari: 18.1

Used Package Manager

npm

Expected Behavior

Note

I originally thought this was an issue with the <Await> component, but I've since realized that the underlying behavioral change is with serverLoader(), and I assume by extension turbo-stream

With v3_singleFetch enabled, a redirect Response received from serverLoader() should result in a rejected Promise.

Actual Behavior

With v3_singleFetch enabled, a redirect Response received from serverLoader() results in a resolved Promise.

When used with <Await>, note that the Response instance is passed to the children function if provided, which breaks the type contract for <Await>:

export function loader() {
  if (someCondition) {
    throw redirect('/');
  }

  return {
    foo: 'bar',
  };
}

export function clientLoader({ serverLoader }: ClientLoaderFunctionArgs) {
  return {
    promise: serverLoader<typeof loader>(),
  }
}

clientLoader.hydrate = true;

export default function RouteComponent() {
  const { promise } = useLoaderData<typeof clientLoader>();

  return (
    <Suspense fallback={<>Loading...</>}>
      <Await resolve={promise}>
        {/*
        Here, the typings say that data is of type `{ foo: string }`, but at runtime
        if `someCondition` is true it will be a `Response` instance with a 302 status
        and `Location` header.
        */}
        {(data) => <Render data={data} />}
      </Await>
    </Suspense>
  );
}

[brophdawg11]

This will be included in the next release

[github-actions]

🤖 Hello there,

We just published version 2.15.2-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 2.15.2 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!