original.name="UnionType_Invalid_10"
js.execute.ignore=true
======
>>> main.whiley
type nat is (int n) where n >= 0
type natlist is nat[]

type nlt is nat | natlist

function g(int y) -> nlt:
    return (nlt) y

public export method test():
    g(0)
    g(-1)
---
E702 main.whiley 7,11:17
E717 main.whiley 7,4:17