Webpack 4 + Babel 7.4.0 + Babel Polyfill

问题: I am trying to improve the support for my application which is written in ES6 via @babel/polyfill and the browserlist support. I've followed all the instructions over on ht...

可以将文章内容翻译成中文,广告屏蔽插件会导致该功能失效:

问题:

I am trying to improve the support for my application which is written in ES6 via @babel/polyfill and the browserlist support. I've followed all the instructions over on https://babeljs.io/docs/en/babel-polyfill but I think I am missing something.

My browserlist support is defined via my package.json. I am validating whether the install has worked by checking for Array.from (which is used throughout the code) polyfill.

Any ideas why I can't see the polyfills in the compiled code? I use to declare the polyfill in the entrypoint, but the babel docs now says this isn't needed.

If useBuiltIns: 'usage' is specified in .babelrc then do not include @babel/polyfill in either webpack.config.js entry array nor source. Note, @babel/polyfill still needs to be installed.

 ...
  "browserslist": [
    "last 2 version",
    "> 1%",
    "IE 10"
  ],
  "devDependencies": {
    "@babel/core": "^7.4.0",
    "@babel/plugin-syntax-dynamic-import": "^7.0.0",
    "@babel/preset-env": "^7.4.2",
    "babel-core": "^6.26.3",
    "babel-loader": "^8.0.0-beta.4",
    "babel-preset-env": "^1.7.0",
    "chromedriver": "^2.41.0",
    "clean-webpack-plugin": "^0.1.19",
    "copy-webpack-plugin": "^4.6.0",
    "css-loader": "^1.0.0",
    "cssnano": "^4.1.4",
    "env2": "^2.2.2",
    "file-loader": "^1.1.11",
    "html-critical-webpack-plugin": "^2.1.0",
    "html-webpack-plugin": "^3.2.0",
    "lunr": "^2.3.5",
    "mini-css-extract-plugin": "^0.4.1",
    "nightwatch": "^0.9.21",
    "node": "^7.10.1",
    "node-sass": "^4.11.0",
    "optimize-css-assets-webpack-plugin": "^5.0.1",
    "replace-in-file-webpack-plugin": "^1.0.6",
    "sass-loader": "^7.0.3",
    "selenium-server": "^3.14.0",
    "selenium-standalone": "^6.15.6",
    "style-loader": "^0.21.0",
    "webpack": "^4.17.2",
    "webpack-cli": "^3.1.0",
    "webpack-dev-server": "^3.2.1",
    "webpack-merge": "^4.1.3"
  },
  "dependencies": {
    "@babel/polyfill": "^7.4.0",
    "bootstrap": "^4.1.3",
    "handlebars": "^4.1.0",
  }

My .babelrc file looks like the following:

{
    "presets": [
        [
            "@babel/preset-env", {
                "useBuiltIns": "usage"
            }
        ]
    ],
    "plugins": ["@babel/plugin-syntax-dynamic-import"],
}

My webpack file looks like this:

{
    test: /.js$/,  
    use: {
        loader: 'babel-loader',
        options: {
            presets: ['@babel/preset-env']
        }
    }
}]

回答1:

In the components where your fancy stuff is add

import "@babel/polyfill";

At least that's what I had to do with Babel 7, Webpack 4 and React. I know the docs say otherwise but I haven't seen examples that would work with my stack.