Babel 7 and babel-polyfill - babeljs

Question

After updating to babel 7 beta, looks like babel polyfill does not transpile before bundle. I updated all scoped packages like this one "#babel/polyfill": "7.0.0-beta.36". And changed imports for two files from import 'babel-polyfill' to import '#babel/polyfill'. How to use babel/pollyfill with babel env and babel 7. Should I use babel/polyfill when use useBuiltIns: 'usage', with targets?
.babelrc.js
const nodeEnv = process.env.NODE_ENV || 'development'
let presetEnvConfig, plugins
if (nodeEnv === 'test'){
presetEnvConfig = {targets: {node: 'current'}}
plugins = ['istanbul']
} else {
presetEnvConfig = {
targets: {
browsers: ['last 2 versions', 'ie >= 11']
},
modules: false
}
plugins = ['react-hot-loader/babel']
}
const config = {
presets: [
['#babel/preset-env', presetEnvConfig],
'#babel/react',
'#babel/stage-2'
],
plugins,
}
types.js
import keyMirror from '../../../utils/keyMirror'
export default keyMirror({
Unassign: null,
Reassign: null,
QuickAssignment: null,
}, 'TagAssignmentTypes')
index.js
<Assignment
assignee={assignee}
tagId={tagId && tagId.toString(16)}
assignmentType={assignmentTypes.Reassign}
onRequestClose={() => this.setState({isAssignmentInProgress: false})}
onChange={onChange}
/>

Answer 1

#babel/polyfill is a wrapper package which only includes imports of stable core-js features (in Babel 6 it also included proposals) and regenerator-runtime/runtime, needed by transpiled generators and async functions. This package doesn't make it possible to provide a smooth migration path from core-js#2 to core-js#3: for this reason, it was decided to deprecate #babel/polyfill in favor of separate inclusion of required parts of core-js and regenerator-runtime.
Instead of
import "#babel/polyfill";
you should use those 2 lines:
import "core-js/stable";
import "regenerator-runtime/runtime";
Don't forget install those dependencies directly!
npm i --save core-js regenerator-runtime

Answer 2

Change
#babel/stage-2 to #babel/preset-stage-2

Answer 3

The following worked for me, add
**.babelrc**
{
"presets": [
["#babel/env"]
]
}
**app.js**
import "core-js/stable";
import "regenerator-runtime/runtime";
*Install as pointed by gianmarco*
npm i --save core-js regenerator-runtime