Enable generators

[gaearon]

This bundles the regenerator runtime when you use the generator syntax.
It would fix #125 and be the first step towards #51.

One issue I’m seeing right now is that minified bundle increases by 5kB min+gzip even if you don’t use generators because transform-runtime currently externalizes Babel helpers whether you want it or not, and they bring in some stuff from core-js including Symbol.

@kittens said he’s open to fixing it on Babel side by adding helpers: [true] to transform-runtime so we can turn them off.

[sebmck]

@kittens said he’s open to fixing it on Babel side by adding helpers: [true] to transform-runtime so we can turn them off.

helpers: false babel/babel#3603

[taion]

@gaearon @kittens

That doesn't seem like the right fix. Wouldn't it make more sense to either compile babel-runtime without the runtime transform, or else not pull in polyfills in helpers when polyfilling is disabled?

Those helpers shouldn't be pulling in polyfills via sniffing for their existence.

All else being the same, just externalizing the helpers ought to decrease bundle size.

[taion]

It seems like a bug that using babel-runtime makes https://github.com/babel/babel/blob/v6.11.6/packages/babel-helpers/src/helpers.js#L8-L12 pull in a Symbol polyfill.

[hzoo]

Released babel-plugin-transform-runtime@6.12.0 with the PR ^