React IE11 async causes Expected } error - reactjs

Question

I'm trying a tutorial for a basic react web app and it works perfectly in chrome. Here is my code:
import React, {Component} from 'react';
export default class App extends Component {
async componentDidMount() {
const [r1,r2] = await Promise.all([
fetch('http://api.mywebsite.com/content/cars'),
fetch('http://api.mywebsite.com/content/aircrafts'),
]);
this.setState({content:await r1.json(),content2: await r2.json()});
}
render() {
if(this.state) {
console.log(this.state);
}
return (
<div>hello</div>
)
}
}
This works exactly as I expect in Chrome - load up the react component, fetch some data, set the state, and print the state to console.
However, this code will not run in Internet Explorer 11. All I get is a blank page, and in my developer tools, I get the error
Expected '}'
When I click on the link to the error, it highlights this segment of code:
_createClass(App, [{
key: 'componentDidMount',
value: async function componentDidMount() {
var _ref = await Promise.all([fetch('http://new.evermight.com/content/index'), fetch('http://new.evermight.com/content/index')]),
_ref2 = _slicedToArray(_ref, 2),
With an arrow pointing to the line value: async function componentDidMount() {.
How do I make this work in Internet Explorer 11? I only want setState to fire after the fetch calls and such are complete. I need the await behaviour.
EDIT
I am using webpack to compile my project. And if it helps, here is my package.json file:
{
"name": "scroll",
"version": "0.1.0",
"private": true,
"dependencies": {
"animated": "^0.2.1",
"es2015": "0.0.0",
"gsap": "^1.20.3",
"history": "^4.7.2",
"jquery": "^3.2.1",
"react": "^16.1.1",
"react-dom": "^16.1.1",
"react-ga": "^2.4.1",
"react-router-dom": "^4.2.2",
"react-scripts": "0.9.5",
"react-transition-group": "^1.2.0",
"scrollmagic": "^2.0.5",
"video-element": "^1.0.3"
},
"devDependencies": {
"babel-core": "^6.26.0",
"babel-loader": "^7.1.1",
"babel-preset-es2015": "^6.24.1",
"babel-preset-react": "^6.24.1",
"clean-webpack-plugin": "^0.1.17",
"css-loader": "^0.25.0",
"eslint": "^4.13.0",
"eslint-config-aqua": "^2.0.1",
"eslint-plugin-react": "^7.5.1",
"file-loader": "^0.9.0",
"node-sass": "^3.10.1",
"sass-loader": "^4.0.2",
"style-loader": "^0.13.1",
"uglifyjs-webpack-plugin": "^1.1.6",
"url-loader": "^0.5.7",
"webpack": "^3.8.1"
},
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test --env=jsdom",
"eject": "react-scripts eject"
}
}
And here is my webpack.config.js
var webpack = require('webpack');
var CleanPlugin = require('clean-webpack-plugin');
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
module.exports = {
entry: {app:'./src/Index.js'},
output: {
filename: '[name].bundle.js',
chunkFilename: '[id].[hash].bundle.js',
path: '/var/www/html/public/build',
publicPath: '/build/'
},
plugins: [
// This plugin minifies all the Javascript code of the final bundle
new UglifyJsPlugin({
uglifyOptions:{
mangle: true,
compress: {
warnings: false, // Suppress uglification warnings
},
}
}),
new webpack.optimize.CommonsChunkPlugin({
name: 'main', // Move dependencies to our main file
children: true, // Look for common dependencies in all children,
minChunks: 2, // How many times a dependency must come up before being extracted
})
],
module: {
loaders: [
{ test: /\.js$/, exclude: /node_modules/, loader: 'babel-loader?presets[]=es2015&presets[]=react' },
{ test: /\.scss$/, loaders: [ 'style-loader', 'css-loader', 'sass-loader' ]},
{ test: /\.(jpg|gif|png|otf|eot|woff|svg|ttf)(\?.*)?$/, loader: "file-loader" }
]
}
}

Answer 1

Actually, I did get async and await to work in IE11. In my question, I also had a problem with fetch not being supported in IE11. Here's what I did to solve both problems. I went to my bash terminal and typed this
npm install --save es6-promise
npm install --save-dev babel-polyfill
npm install --save-dev babel-plugin-transform-async-to-generator
npm install --save isomorphic-fetch
Next, I added these two lines to the very beginning of my src/Index.js before any other code because it is my entry point:
import "babel-polyfill";
import "isomorphic-fetch";
Then I ran the webpack command, and now my IE11 supports the code I created with async await and it supports the fetch command.

Answer 2

async-await is not supported in IE.
Check the MDN docs
You need to use Promises instead like
componentDidMount() {
Promise.all([
fetch('http://api.mywebsite.com/content/cars'),
fetch('http://api.mywebsite.com/content/aircrafts'),
]).then(([r1, r2]) => {
this.setState({content:r1.json(),content2: r2.json()});
})
}
Also in order to support promises in IE, you need to use a 3rd party Polyfill libraries like BlueBird or use babel-polyfill