Declare the return type here

[azizoid]

we could declare the return type in the Hook call, with
const data = useLoaderData<WierdDataProps>()

export declare function useLoaderData<T>(): T;

react-router/packages/react-router/lib/hooks.tsx

Line 749 in 892238b

export function useLoaderData(): unknown {

[cmmartti]

Just typecast it with as. It's functionally equivalent.

const data = useLoaderData() as WeirdDataProps;

[azizoid]

that is fast and temporary solution. Not the correct way.