type of intersection of loose objects is invalid

[pandanoir]

Problem

I used $intersection to define the types baseType & (typeA | typeB), but type inference does not work.

const baseType = $object({ common: $string }, false);
const typeA = $object({
    type: $const("a"),
    data: $number,
  }, false),
  typeB = $object({
    type: $const("b"),
    data: $string,
  }, false);

const validate = $intersection([$union([typeA, typeB]), baseType]); // expect: (typeA | typeB) & baseType
const x: Infer<typeof validate> = { type: "a", data: 42, common: "" }; // type error (because Infer<typeof validate> is {common: string})

validate itself is working as intended.

console.log(validate({ type: "a", data: 42, common: "" }) === true);
console.log(validate({ type: "b", data: "str", common: "" }) === true);

console.log(validate({ type: "a", data: 42 }) === false);
console.log(validate({ type: "a", data: "str", common: "" }) === false);
console.log(validate({ type: "b", data: 42, common: "" }) === false);

Expected Behavior

Infer<typeof validate> should be ({ type: 'a'; data: number } | { type: 'b'; data: string }) & { common: string }.

[pandanoir]

type MapInfer<T> = T extends [infer x, ...infer xs]
  ? [Infer<x>, ...MapInfer<xs>]
  : [];

export const $intersection = <Vs extends Validator<any>[]>(
  validators: readonly [...Vs]
): Validator<TupleToIntersection<MapInfer<Vs>>> => {

This code probably solves the problem. However, I'm worried that the breaking change to the $intersection type would not be a problem.

(type of intersection of exact objects is still invalid. $intersection([$object({ data: $number }), $object({ common: $string })]))