I also suggest to add prettier and yarn to the list.

As I said in #1096 (comment)

And first problem.

According to the spec - es6 classes can not be called as a functions.

Few solutions:

Make a breaking change and disalow var map = Map() syntax in favor of var map = new Map().
Refactor all es6 classes to Function.prototype style.
Keep using declassify (but first - need to fix it for latest rollup).

Oh, spec changed, now i'll try Bublé tonight.

Using new with collections is actually an anti pattern. They're designed to be used like the JS scalar types (Number, String) as just a callable function.

That does mean the class syntax either needs to only ever be consumed by an off-spec transformer or it needs to be converted to use MapPrototype.method = function(){} or rely on Object.create's extra properties param or something like that

I think it's safe to call this task done. There's always more modernization to be done, but this hits the major objectives.

Thanks so much for your help, @umidbekkarimov!

@leebyron yep 👍 for docs need to update react, react-router and jump from gulp to webpack+webpack-dev-server. I guess it's good first bug for facebook juniors 😜