Node 8 (async/await)

[mxstbr]

The backpack Babel preset does a bunch of stuff to make async/await supported in environments that don't support it:

backpack/packages/babel-preset-backpack/index.js

Lines 24 to 41 in 5fa5008

	[require.resolve('babel-plugin-transform-regenerator'), {
	// Async functions are converted to generators by babel-preset-env (which
	// is based on babel-preset-latest)
	async: false
	}],
	// This is so we don't need to add `babel-polyfill` to our webpack `entry`.
	// Unlike `babel-polyfill`, `babel-runtime` + the transform do not pollute
	// the global namespace. Yay.
	// @see https://medium.com/@jcse/clearing-up-the-babel-6-ecosystem-c7678a314bf3#.7j10g8yn0
	[require.resolve('babel-plugin-transform-runtime'), {
	helpers: false,
	polyfill: false,
	regenerator: true,
	// Resolve the Babel runtime relative to the config.
	moduleName: path.dirname(require.resolve('babel-runtime/package'))
	}]

The issue is that as of the Node 8 LTS release it's totally unnecessary since it supports async/await out of the box! To get it to build with vanilla async/await (not transpiled to generators) I had to opt-out of the shared Babel config and basically just run with this .babelrc:

{
  "presets": [
    [
      "env",
      {
        "targets": {
          "node": "current"
        },
        "useBuiltIns": true,
        "exclude": [
          "babel-plugin-transform-regenerator",
          "transform-async-to-generator"
        ]
      }
    ]
  ],
  "plugins": [
    "transform-flow-strip-types",
    "transform-object-rest-spread",
    "babel-plugin-transform-react-jsx",
    "syntax-dynamic-import"
  ]
}

It'd be A+++ super awesome if backpack did the right thing™️ for Node 8 by default, i.e. didn't transpile generators at all and didn't include regenerator in the bundle. 😊

[jaredpalmer]

Very much agree

[jaredpalmer]

Definitely a breaking change though.

[mxstbr]

Maybe we could use process.version to include things optionally if a user is on Node < 8?

[yoyo837]

It is best to be able to automatically sniff using a different configuration.