`unevaluatedProperties` failed verification when combined with `Type.Intersect` and `Type.Union` about typebox HOT 2 OPEN

@eygsoft Hi! Thanks for reporting!

Yes, this looks like a bug. At this stage, I don't think I'll be able to take a look into the issue until the weekend at the earliest (as I am currently tied up with some other work), however you may be able to workaround this issue if you can reshape the schematics into the following.

const A = Type.Object({
 a: Type.String(),
 b: Type.String()
}, { additionalProperties: false })

const B = Type.Object({
 a: Type.String(),
 c: Type.String()
}, { additionalProperties: false })

const T = Type.Union([A, B]) // T = { a: string, b: string } | { a: string, c: string }

This issue actually crosses over with some other areas of the library where I'm looking to implement a distributive evaluate similar to the following....

TypeScript Link Here

type T = (
  { x: number }
) & (
  { y: number } |
  { z: number }
)

// non-distributive: where passing y | z is observed as unevaluated properties

type A = {[K in keyof T]: T[K]} & {} // type A = { x: number }

// distributive: where y | z are distributed with outer property x

type E<T> = {[K in keyof T]: T[K]} & {}

type B = E<T>                       // type B = { x: number; y: number; } | 
                                    //          { x: number; z: number; }

Note that TypeBox observes the validating schematic as A, where it should be observed as B. The validator should apply distributive union rules to the schematics (which has been challenging at a type level, but may be more tenable at a validation level)

Will keep you posted on any changes here.
Cheers
S

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