The article mentions that async/await functionality hasn't landed in Javascript yet. I wonder if you can get the same functionality today using scala.js [0] and the scala/async [1] library.

I believe it should work. The scala/async library is just a set of macros that transform blocks of code using async/await into for comprehensions.

[0] http://www.scala-js.org [1] https://github.com/scala/async