Upgrade babel

[bhollis]

No description provided.

[bhollis]

This is where our 5% increase comes from!

[merceyz]

Try adding

version: require('@babel/runtime/package.json').version

here

DIM/babel.config.js

Lines 10 to 13 in ab6172f

	'@babel/plugin-transform-runtime',
	{
	useESModules: true
	}

[merceyz]

Don't know if this will reduce the bundle size but you can also add

corejs: require('core-js/package.json').version

here

DIM/babel.config.js

Lines 49 to 56 in ab6172f

	'@babel/preset-env',
	{
	modules: false,
	loose: true,
	useBuiltIns: 'usage',
	corejs: 3,
	shippedProposals: true
	}

Looking at https://babeljs.io/docs/en/babel-preset-react you can remove corejs from here

DIM/babel.config.js

Line 58 in ab6172f

['@babel/preset-react', { useBuiltIns: true, loose: true, corejs: 3 }]

[bhollis]

Nope, looks like that didn't help.

[bhollis]

Comparing the sources, it looks like after upgrading babel we're no longer transpiling to latest-browser-supported features. It's going all the way back to es5 - no arrow functions, etc.

[bhollis]

Filed babel/babel#10945 - I dug through the babel-preset-env code but I don't see where it could be going wrong in understanding our babel-preset-env query.

[delphiactual]

we can temporarily add "not android <= 79" to package.json

[bhollis]

@delphiactual I have a more comprehensive fix in #4839.