How to fix regeneratorRuntime error async method with babel 7.5 + runtime + plugin-transform-runtime

Question

I try to use async/await on a js script (class method) in a webpack config but i have got this error :

search.js:33 Uncaught ReferenceError: regeneratorRuntime is not defined

I have maybe an error in the babelrc file but i tried all things found on the web :/

Stack : WSL1 node 10.16.3 npm 6.11.1 in Visual Studio Code.

Previously, i had polyfill config with a similar problem. I tried to use new Babel recommandations with @babel/plugin-transform-runtime and @babel/runtime but the issue persists.

I tried to remove /node_modules/ directory and lock package files to generate it again with npm i but nothing changes.

I have no problem with an async function declaration (outside a class).

File with generated error

class Search {

    constructor() {...}

    async run() {
        await this.xxxx();
    }

    xxxx() {...}
}

.babelrc

{
  "presets": [
    ["@babel/preset-env"],
    [
      "@babel/env",
      {
        "modules": false,
        "useBuiltIns": "usage",
        "corejs": 3
      }
    ]
  ],
  "plugins": [
    [ "@babel/plugin-transform-runtime", {"regenerator": true, "corejs": 3} ],
    [ "@babel/plugin-transform-async-to-generator" ]
  ]
}

package.json

{
  ...

  "devDependencies": {
    "@babel/core": "^7.5.5",
    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
    "@babel/plugin-transform-async-to-generator": "^7.5.0",
    "@babel/plugin-transform-runtime": "^7.6.2",
    "@babel/preset-env": "^7.6.3",
    "autoprefixer": "^9.6.1",
    "babel-loader": "^8.0.6",
    "clean-webpack-plugin": "^2.0.2",
    "css-loader": "^2.1.1",
    "file-loader": "^3.0.1",
    "fontmin-webpack": "^2.0.4",
    "imagemin-gifsicle": "^6.0.1",
    "imagemin-jpegtran": "^6.0.0",
    "imagemin-optipng": "^7.0.0",
    "imagemin-svgo": "^7.0.0",
    "imagemin-webpack": "^5.1.0",
    "jquery": "^3.4.1",
    "loader": "^2.1.1",
    "mini-css-extract-plugin": "^0.5.0",
    "node-sass": "^4.12.0",
    "optimize-css-assets-webpack-plugin": "^5.0.3",
    "postcss-cli": "^6.1.2",
    "postcss-import": "^12.0.1",
    "postcss-loader": "^3.0.0",
    "postcss-preset-env": "^6.7.0",
    "sass-loader": "^7.3.1",
    "style": "0.0.3",
    "style-loader": "^0.23.1",
    "sugarss": "^2.0.0",
    "uglifyjs-webpack-plugin": "^2.2.0",
    "webpack": "^4.39.2",
    "webpack-cli": "^3.3.7",
    "webpack-manifest-plugin": "^2.0.4"
  },
  "dependencies": {
    "@babel/runtime": "^7.6.3",
    "core-js": "^3.3.2",
    "detect-it": "^3.0.5",
    "gifsicle": "^4.0.1",
    "slick-carousel": "^1.8.1"
  },
  "browserslist": [
    "last 2 versions"
  ]
}

Answer 1

I found the solution.

In the main js file import "regenerator-runtime/runtime";

Add regenerator-runtime npm i regenerator-runtime

Thanks.