Change type of object property while preserving JSDoc

replace.ts

type Replace<
  Obj extends Record<string, any>,
  Field extends keyof Obj,
  NewType,
> = Reveal<
  { [Key in keyof Obj]: Key extends Field ? NewType : Obj[Key] }
>

type Reveal<Obj extends Record<string, any>> = {
  [K in keyof Obj]: Obj[K]
}
    
// =========================

type X = {
  /** This is a foo. */
  foo: string
}

type Y = Replace<X, 'foo', number>
declare const y: Y
void y.foo // same JSDoc!