Fix wrong inference of return value of withAxiomRouteHandler

[mauriciabad]

withAxiomRouteHandler used to return always NextResponse<unknown>, it was giving me errors in my project.
I also added generics to the other withAxios function, that had the same problem.
And finally, now that the type inference is improved, there's no need to explicitly say that req is AxiomRequest, so I updated the example's code.

Warning

Be aware that I used a type cast that could be unsafe (as T in line 99), because I couldn't manage to do it in any other way. Maybe someone more experienced in TypeScript can find a better solution, but for now, mine is "good enough".

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Name	Status	Preview	Comments	Updated (UTC)
next-axiom-example	❌ Failed (Inspect)			Jan 27, 2024 7:31am

[mauriciabad]

This is the unsafe cast I mean.

If you do this, which would be the proper way, there is a type error I can't fix:

export function withAxiomRouteHandler<T extends AxiomHandler>(handler: T): T {
  const result: T = async (req, arg) => { ... }
  return result
}

Type '(req: AxiomRequest, arg: any) => Promise<Response | NextResponse<unknown>>' is not assignable to type 'T'.
  '(req: AxiomRequest, arg: any) => Promise<Response | NextResponse<unknown>>' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'AxiomHandler<any, Response | NextResponse<unknown>>'.ts(2322)