Running tutorial from localhost

[sdurandeu]

I was trying to run this from localhost using serve. However, when launching the app from the https://code.cerner.com portal I got this TypeError: Cannot read property 'substr' of undefined error. I wonder if it has to do with some kind of restriction about running apps on localhost/without HTTPS? I haven't found anything in the code that prevents using localhost, so it's maybe the OAuth2 server?

The underlying error is explained here, but I doubt upgrading the library will fix anything: smart-on-fhir/client-js#22

Any thoughts?