Uncaught ReferenceError: regeneratorRuntime is not defined

解決策

webpack.config.js

require("babel-polyfill");
module.exports = {
  entry: ["babel-polyfill", "./src/main.js"],

.bablerc

{
    "presets": [
        "@babel/preset-env",
        "@babel/preset-react"
    ],
    "plugins": [
        "transform-class-properties"
    ]
}

react+webpackしながらasync/await使おうとした時に出たエラーの対処方法

環境

    "@babel/cli": "^7.1.0",
    "@babel/core": "^7.1.0",
    "@babel/node": "^7.0.0",
    "@babel/preset-env": "^7.1.0",
    "@babel/preset-react": "^7.0.0",
    "babel-loader": "^8.0.2",
    "babel-plugin-transform-class-properties": "^6.24.1",
    "babel-polyfill": "^6.26.0",
    "webpack": "^4.17.1",
    "webpack-cli": "^3.1.1",
    "webpack-command": "^0.4.1",
    "react": "^16.5.2",
    "react-dom": "^16.5.2"

参考

github.com