Union with Type.Undefined() produces any about typebox

[sinclairzx81]

Hi,

Thanks for letting me know. The Type.Undefined() is actually part of the extended TypeBox API and isn't intended to be used as part of Type.Object({}) schemas (in the current version of TypeBox anyway, this may change in later revisions of this project). The extended set of types provided by TypeBox are detailed here https://github.com/sinclairzx81/typebox#typebox--typescript-1

As an alternative, you can replace Type.Undefined() with Type.Optional() which modifies the object property with both undefined and ? - possibly undefined on the inferred object type.

Example

const Nullable = <G>(T: G) => Type.Union([T, Type.Null()]) 

const TNews = Type.Object({
    mediaUrl: Type.Optional(Nullable(Type.String())),
    link: Nullable(Type.String())
})

type News = Static<typeof TNews>

// type News = {} & {
//     mediaUrl?: string | null | undefined;
// } & {
//     link: string | null;
// }

Also ensure you have strict: true enabled in your tsconfig.json. I have tested on TS 8.3.8 and should work ok. Note that future revisions of TypeBox may mandate on latest versions of the TS compiler. (TypeScript inference rules do change from time to time and this project will seek to align with the most current releases of TypeScript moving forward).

Hope this helps :)

[invalidred]

That can work. Thank you for taking the time to respond, really appreciate your help. Also thank you for creating a wonderful library. Cheers.