type InferUnion<TBase, TIncoming> = TBase extends BuiltInType ? TBase | TIncoming : TIncoming extends BuiltInType ? TBase | TIncoming : TBase extends ReadonlyArray<unknown> ? TIncoming extends ReadonlyArray<unknown> ? InferUnion<TBase[number], TIncoming[number]>[] : TBase | TIncoming : TBase extends object ? TIncoming extends object ? InferUnionObject<TBase, TIncoming> : TBase | TIncoming : TBase | TIncoming;