@tanstack/react-router (Typescript) - how to get the string of union types that's auto-generated for Link.to prop?

Question

Just like the title! The typescript support with tanstack is a lifesaver, but I would like to know how to get the actual type for the generated route paths.

For example, there's typescript support for the <Link to="/some-route">. Is there any way to get the type of the to prop?

I tried importing and playing around with other types from @tanstack/react-router, but couldn't find anything. I also could not find any documentation on this.

Answer 1

Tanstack Router can automatically generate a route tree file that includes types related to routing. I created an example app using command: npm create @tanstack/router@latest, and I found the following code in src/routeTree.gen.ts:

export interface FileRoutesByTo {
  '/': typeof IndexRoute
  '/about': typeof AboutRoute
}

This file is automatically updated when new files are added under the route directory while Vite is running. The routing file setup is handled in vite.config.ts using TanStackRouterVite() plugin:

export default defineConfig({
  plugins: [TanStackRouterVite({}), react()],
})

For example, you can customize the name of the generated route tree file by using the generatedRouteTree option. (the default is src/routeTree.gen.ts)

Note: This explanation applies to File-Based Routing. Other routing methods might have different configurations.

---

edited:

Wrapper component example:

type extendedLinkProps = Omit<LinkProps, "to"> & {
  to: string
}

type toType = LinkProps['to'];
function isToType(value: any): value is toType {
  // Add appropriate type checks here.
  return true;
}

export const ExtendedLink = ({to, children, ...linkProps}: extendedLinkProps) => {
  const path = convertToToPath(to); // e.g. "/example/$id"
  const param = convertToToParam(to); // e.g. "1"
  type toType = LinkProps['to'];
  if (!isToType(path)) return;
  return <Link {...linkProps} to={path} params={param}>{children}</Link>
}

use it like:

<ExtendedLink to="/example/1">
  example
</ExtendedLink>

I think it works, but has not been tested.