Generated enum type for `routeId`

[Conduitry]

Describe the problem

$page.routeId is just a string currently, which means you can have typos that won't match the ID of any route. It would be nice if this were typed, so that typos will be caught as type errors, and so that any renamed pages or moved routes will also result in type errors if their corresponding $page.routeIds aren't also updated.

Describe the proposed solution

We know the route manifest at build time. We should be able to construct a 'foo' | 'bar' | 'baz' type that the routeId would adhere to. The question would be where this generated type ought to live and how it ought to be accessed by the app code. Ideally, people could just keep using the ambient $app/stores types, and these would pull in the appropriate enum from .svelte-kit.

Alternatives considered

No response

Importance

nice to have

Additional Information

No response

[benmccann]

One thing to think about when deciding whether/how to implement this - if we added the ability to import routes from another project I'm not quite as sure how to support that

[minht11]

Currently RouteId and LayoutIds have generated types, but are not exported

you can access it somewhat with type RouteId = LayoutLoadEvent['route']['id'] would exporting it directly be possible?

In my case I am using route id to have different view transitions on different routes, I changed routes names but forgot to change route ids, having explicit types would have caught that.