whiley_test_file 0.6.2

=====
>>> main.whiley
import string from js::core

function isJsString(null|string ns) -> bool:
    return ns is string

public export method test():
    assume !isJsString(null)
    assume isJsString("hello world")
>>> js/core.whiley
package js

public type string is int[] where true
---