[Bug]: Type of loaderData wrong when returning redirect in the loader (action as well)

[rapnuss]

What version of React Router are you using?

7

Steps to Reproduce

export const loader = () => {
  if (Math.random() < 0.5) {
    return redirect('/')
  }
  return {some: 'data'}
}

export default function Home() {
  const data = userLoaderData<typeof loader>()
  return <>{data.some}</> // ERROR: some not in type {headers: ...}
}

Expected Behavior

some should be defined on the loaderData

Actual Behavior

there is a typescript error

[Moonflower-labs]

Hi, I had a similar issue. If you throw the redirect instead of returning it, the typescript error should go away.

[goamaan]

Facing the same problem - just migrated from remix to rr7 and the inferred return types for actions/loaders are messed up. I'm returning a redirect / createUserSession from my actions and this used to work but now shows a type error when trying to access anything on fetcher.data (when using const fetcher = useFetcher<typeof action>() in RR7

[brookslybrand]

Since redirect returns a response, you'll want to throw it to get the proper types, otherwise the inference thinks you're returning an object

[goamaan]

Confused as to why this did work in Remix though?

[brookslybrand]

Confused as to why this did work in Remix though?

Good point, not sure if there was something we should be carrying over from Remix

c.c. @pcattori

[goamaan]

Also, if I need to redirect the user after logging in, I do something like this in my action

return createUserSession({
            request,
            userId: user.id,
            email,
            roles,
            remember: true,
            redirectTo: redirectTo ?? "/app",
            isAdmin: user.isAdmin,
        })

where createUserSession is this

async function createUserSession({
    request,
    userId,
    remember,
    redirectTo,
    roles,
    email,
    isAdmin,
}: {
    ...
}) {
    const { session } = await getSession(request)
    ...
    session.set(IS_ADMIN, isAdmin)
    return redirect(redirectTo, {
        headers: {
            "Set-Cookie": await commitSession(session, {
                maxAge: remember
                    ? 60 * 60 * 24 * 2 // 2 days
                    : undefined,
            }),
        },
    })
}

in this case throwing doesn't seem work Nvm it does work, I just have to throw from createUserSession instead of from the action

[pveyes]

The fix is to exclude Response type from loader and action. I've created a draft PR, but not sure what tests to add (and how) considering it's a type fix

[Varkoff]

Also, if I need to redirect the user after logging in, I do something like this in my action

return createUserSession({
            request,
            userId: user.id,
            email,
            roles,
            remember: true,
            redirectTo: redirectTo ?? "/app",
            isAdmin: user.isAdmin,
        })

where createUserSession is this

async function createUserSession({
    request,
    userId,
    remember,
    redirectTo,
    roles,
    email,
    isAdmin,
}: {
    ...
}) {
    const { session } = await getSession(request)
    ...
    session.set(IS_ADMIN, isAdmin)
    return redirect(redirectTo, {
        headers: {
            "Set-Cookie": await commitSession(session, {
                maxAge: remember
                    ? 60 * 60 * 24 * 2 // 2 days
                    : undefined,
            }),
        },
    })
}

in this case throwing doesn't seem work Nvm it does work, I just have to throw from createUserSession instead of from the action

I had the same issue. In Remix 2.x, returning a redirect somehow worked and didn't mess with the loader / action types.

Having to " throw " a successful authentication request seems a bit weird to me. And it introduces a strange behavior in my app, I need to fully reload before showing the authenticated user info.

[sdifru]

Is it the recommended practice to throw redirect? I read the docs and it shows that it returns redirect, not throwing it.

[GrahamQuan]

same here, i end up with undefined | dataType like

import { redirect } from 'react-router';
import type { Route } from './+types/blog';

type BlogType = {
  userId: number;
  id: number;
  title: string;
  body: string;
};

export async function loader({ params }: Route.LoaderArgs) {
  const data = await fetch(
    `https://jsonplaceholder.typicode.com/posts/${params.id}`
  );
  if (!data) {
    redirect('/');
    return; // return undefined as default
  }

  return (await data.json()) as BlogType;
}

export default function Blog({
  params,
  loaderData,
}: Route.LoaderArgs & Route.ComponentProps) {
  // check if loaderData is undefined
  if (!loaderData) {
    return null;
  }

  return (
    <div>
      <h1>blog id: {params?.id}</h1>
      <p>{loaderData.title}</p>
      <p>{loaderData.body}</p>
    </div>
  );
}

edit:
looks like they throw it instead of return
#12506