I'm years behind on Javascript (I'm circa 'AJAX is new' in my knowledge) but I've been having good luck catching up using the Babel REPL with small snippets to just see how the new features get translated into the Javascript I know. Seeing what the compiler renames is a good way to understand the new scoping rules, etc.

It's been especially helpful for yield and async/await, but I wonder if there's a bug in Babel with async/await. Just using the code sample from the article:

  function fetchUserName() {
    return new Promise(resolve => setTimeout(resolve, 500))
  }
      
  async function withAsync() {
    print("withAsync: fetching...")
    await fetchUserName()
    print("withAsync: done")
  }
  await withAsync()

when I set the target to be 'ie 6', so hopefully I get output that's only the Javascript that I know, most of this gets translated to (a lot of) Javascript that looks normal for 2005 Javascript - except the last 'await' line is still there. Is that a bug/limitation in Babel or was 'await' present in Javascript from years ago?