Add babel7 config

[christianalfoni]

No description provided.

[CompuIves]

This is solid, I love the line deletions with it! I left some comments with some questions. I'm mostly curious how this will affect the bundle size and speed(!) compared to babel 6. I remember doing some dark magic with polyfills in https://github.com/CompuIves/codesandbox-client/blob/master/packages/common/load-dynamic-polyfills.js. Might be interesting to look at.

Very nice! Let's merge this in soon 😄.

[CompuIves]

I'm wondering if this would make the bundler bigger than it needs to be, since with this it's including all babel polyfills out there. Is there a way to make this more fine-grained? I thought that babel-preset-env would do something like this.

[christianalfoni]

Yeah, I think we only need a setImmediate poly... which can basically just be:

global.setImmediate = global.setImmediate || global.requestAnimationFrame

Will try to remove that and only use custom stuff inside existing polyfill file there

[CompuIves]

Can we show the spinner after a set time, like 1s? That will make perceived loading speed faster and is what Loadable has been doing.

[christianalfoni]

Jup, for sure, let me fix :)

[CompuIves]

It seems like this 'env' has been unchanged, but that should work too, right?

[christianalfoni]

Ah, let me fix that, just to be certain it uses the new stuff

[CompuIves]

I'm thinking that we should replace this target with something sensible for CodeSandbox, like 99%>. I will check the analytics.

[christianalfoni]

Great, do that :)

[christianalfoni]

Okay, so I had to do some additional work here. Mostly fixing testing. With Babel 7 there are some adjustments to how Jest finds and handles test files.

• It is supposed to find a babel.config.js file at root of lerna project... which it does. But the pattern matching for node_modules does not work for some reason. I believe this is a bug. This is fixed by having a babel.config.js file in each package requiring it

• The pattern matching for node_modules has been changed, strengthening my point above, because I had to add a file matcher as well at the end

• I had to install old babel core version 7.bridge, to allow new babel 7 to run with Jest

• There was a need to update snapshots, due to returning a SET instead of an ARRAY. This could maybe be related to React update. The content of the collection is the same, so let it through

It really is insane how difficult it is to maintain these large projects, but I think this move it very important. When you get the "insides" on babel 7 as well there is a lot of cleanup that can be done!

Hopefully the last fix is moving in now. Just add the babel 7 bridge thingy as a dep, while it was also a devDep :)

[christianalfoni]

Not sure what happens on the integration tests there? Any way to run that locally? Or maybe it is related to PR deployment error there? Maybe I broke some production config. Could you help me find some error message? :)