Returning an unboxed string value from an external function can fail.

[mwchase]

I hit this in the same experimentation that led to #26. Casting from strings to StringValues is extremely finicky, in ways I don't quite understand. It appears that round-tripping a string from Ink to js to Ink works, and the string looks like a normal string in the console. But if I return a string defined in JavaScript from an external function, then it will fail unless I use new String("foo"), apparently because "foo" instanceof String is false.
I don't know JavaScript well enough to understand how this behavior is even possible, but it happens.

[erkyrath]

Javascript is terrible. It is known.

You can use the test (typeof(val) == 'string' || val instanceof String) , I'm pretty sure.

[y-lohse]

> 'a' instanceof String
false
> typeof 'a'
"string"

....right. Surely there's a npm module for that!
Just kidding, but yes, the String detection tests ned revision. Thanks for pointing it out! Feel free to submit a PR, otherwise I'll have a look at it when I get the chance.