Async functions are always transformed to regenerator runtime

🐛 bug report

🎛 Configuration (.babelrc, package.json, cli command)

Without config just do

yarn init
yarn add parcel-bundler

create index.js:

(async function () { return await 1 })()

parcel index.js

🤔 Expected Behavior

Without any babel config I would assume no transformation will be made, just bundling into one file.

😯 Current Behavior

Dist file will contain

_asyncToGenerator( /*#__PURE__*/regeneratorRuntime.mark(function _callee() {
...

💁 Possible Solution

🔦 Context

In specific project async functions are transformed no matter what .babelrc I try. I am trying to migrate from browserify but using

node_modules/.bin/parcel build ./src/client/index.js --out-dir ./public --out-file bundle.js --no-minify

will give me code with async functions transformed, where

node_modules/.bin/browserify ./src/client/index.js -o ./public/bundle.js -t [ babelify ]

will keep async functions unchanged. I would expect these to behave the same in regards to babel transforms.

💻 Code Sample

🌍 Your Environment

Software	Version(s)
Parcel	1.6.2
Node	v8.1.4
npm/Yarn	1.3.2
Operating System	Mac

[brandiqa]

Found this solution:

npm install --save-dev babel-plugin-transform-runtime babel-runtime

Create .babelrc file and add:

{
    "plugins": [
        ["transform-runtime",
        {
            "polyfill": false,
            "regenerator": true
        }]
    ]
}

[AbeEstrada]

I was getting this error when using async/await: ReferenceError: regeneratorRuntime is not defined

My solution was adding: import "babel-polyfill";

Leaving this comment for reference.