Babel 7

[hzoo]

👋 Bootstrap team! Making a PR to change to v7 if desired! (instead of by
accident via #22727, hopefully we can fix that kind of dependency issue soon)

• Update packages to Babel 7
• Use https://github.com/babel/babel-preset-env instead of preset-es2015 (just deprecated it), has the same behavior if you don't specify a target
• feel free to edit the pr

Diff

• New loose option for classes removes a bunch of helper checks, so they won't be in the bundle/files anymore, so a smaller output. Via Remove ClassCallCheck, possibleConstructorReturn in loose mode babel/babel#4850

• rm'classCallCheck', 'inherits', 'possibleConstructorReturn'

• add inheritsLoose

• Aliases the class prototype via Fix #4840: Alias class prototype for methods in loose mode babel/babel#5560

• babel-generator defaults to " double quotes now via Hardcode to double quotes, indent to 2 spaces babel/babel#5824

• there are some newline changes because Babel won't read tokens from the AST anymore, so it may look different but it should compile faster (faster parse/print) via Remove whitespace generation babel/babel#5833
• Comments from dead code elim for a minifier if using exports. via Annotating transformed classes with #__PURE__ comment babel/babel#6209

• default for template literals is using concat instead of +, can use loose to go back to + via default to spec mode for template literal transform babel/babel#6098

[hzoo]

maybe don't want to do it this way (or use https://www.npmjs.com/package/cross-env), don't think we support a --environment flag but we could think about it

[Johann-S]

I don't understand that change, --no-babelrc is it deprecated ?

[hzoo]

no it's because there isn't a way to pass options to a preset via cli, so it wouldn't use loose mode

[XhmikosR]

Thanks for the PR @hzoo! One thing, you shouldn't include the dist files in your PR.

/CC @Johann-S for review

[XhmikosR]

I wonder if we should tweak the options to use for example single quotes. And maybe switch to loose for concatenating strings.

[hzoo]

One thing, you shouldn't include the dist files in your PR.

Yeah I kept them in to explain the changes, can be removed later.

And maybe switch to loose for concatenating strings.

I made the individual files use the same config (loose) so that is already done.

should tweak the options to use for example single quotes.

This we just defaulted to quotes and removed the options since it's just the output and not source code.

[XhmikosR]

I'm aware it's the output. Too bad there is no option since I personally am used to single quotes everywhere. Anyway not a big deal I guess.

…

On Sep 16, 2017 23:31, "Henry Zhu" ***@***.***> wrote: One thing, you shouldn't include the dist files in your PR. Yeah I kept them in to explain the changes, can be removed later. And maybe switch to loose for concatenating strings. I made the individual files use the same config (loose) so that is already done. should tweak the options to use for example single quotes. This we just defaulted to quotes and removed the options since it's just the output and not source code. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#23966 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAVVtWtzMgW4aHR0UHSAK5KXUUqoCxbbks5sjDAKgaJpZM4PZ68t> .

[hzoo]

Yeah I hope not 😛, I just picked one - babel/babel#5139

[Johann-S]

Thanks for your PR @hzoo, I thought about doing that change but you were quicker than me 😄

Just remove changes in our dist files and we will merge your PR 👍

[hzoo]

Ok removed the dist, js/dist changes

[Johann-S]

Sorry but they are warning in Travis see : https://travis-ci.org/twbs/bootstrap/jobs/276359245#L618
about : createClass is not exported by babelHelpers those warnings wasn't there before that

[hzoo]

Hm good catch, didn't think that was needed so I removed in rollup.config.js

[hzoo]

Ok I see a change we can make to loose mode for static getters https://babeljs.io/repl/build/master#?babili=false&browsers=&build=&builtIns=false&code_lz=MYGwhgzhAECCIFMBOAXaBvAUNaEVhQEthoBzBNANQFEAlAZQEkB5AOQAoBKDbHaJCgFckAO2g0GLVrwC-mGUA&debug=false&circleciRepo=&evaluate=false&lineWrap=true&presets=es2015-loose&prettier=false&targets=&version=7.0.0-beta.0 which we can fix later.

I also excluded typeof transform so that helper can be dropped. I assume bootstrap doesn't use Symbol so it's not needed.

[Johann-S]

Thanks @hzoo 👍
BTW I think you fix this issue : rollup/rollup-plugin-babel#165 😄