Babel Preset: Update @babel/preset-env to enabled optional chaining

[gziolo]

Optional chaining reached stage 4!

https://twitter.com/NicoloRibaudo/status/1202323456899067906

This means that... it should be soon enabled by default in @babel/preset-env and in @babel/parser.

There are two issues to track progress:

• Enable optional chaining by default in @babel/preset-env babel/babel#10809
• Enable optional chaining by default in @babel/parser babel/babel#10810

Once those two packages are updated and published to npm we should take an action and update @wordpress/babel-preset-default and all other packages using Babel to use the latest version of all Babel packages.

Resources

• https://tc39.es/proposal-optional-chaining/
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining
• https://2ality.com/2019/07/optional-chaining.html

[jsnajdr]

After the Babel update ships and we proceed to update Gutenberg, we'll need to add the shippedProposals: true option to the preset-env configuration. That tells the preset to include features that are not yet part of the published standard (that happens officially once a year), but are already approved (stage 4+) and are shipping in production browsers.

Babel will empty the list of shipped proposals once the standard is published and will enable these features by default. Then the list can grow again over the next year 🙂

[abdel-h]

Hey @jsnajdr we are supposed to add opts.shippedProposals = true; to Babel Preset package right ?

[jsnajdr]

we are supposed to add opts.shippedProposals = true; to Babel Preset package right ?

If the Babel update that adds optional chaining to preset-env makes it a part of the shippedProposals option, then yes, Gutenberg will need to enable that option in its Babel config.

[gziolo]

Babel 7.8 is out with the support for the feature:
https://babeljs.io/blog/2020/01/11/7.8.0