如何在webpack/babel建筑中使用CustomElement v1填充？

Question

虽然webpack，但我很难让此WebComponents填充+本机-shim在所有设备上正常工作。

关于我的设置的一些背景：* Webpack2 + babel-6 * app是用ES6编写的，转到ES5 *导入一个用ES6编写的node_module包，该包定义/注册应用程序中使用的CustomElement。

相应的webpack dev配置如下所示：

const config = webpackMerge(baseConfig, {
  entry: [
    'webpack/hot/only-dev-server',
    '@webcomponents/custom-elements/src/native-shim',
    '@webcomponents/custom-elements',
    '<module that uses CustomElements>/dist/src/main',
    './src/client',
  ],
  output: {
    path: path.resolve(__dirname, './../dist/assets/'),
    filename: 'app.js',
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        loader: 'babel-loader',
        options: {
          cacheDirectory: true,
        },
        include: [
          path.join(NODE_MODULES_DIR, '<module that uses CustomElements>'),
          path.join(__dirname, '../src'),
        ],
      },
    ],
  },
...

键取：*我需要在CustomElement之前加载<module that uses CustomElements> *我需要在应用程序soure * <module that uses CustomElements>是ES6之前加载<module that uses CustomElements>，所以我们正在传送它(因此在babel-loader中包含)。

上述功能在现代ES6浏览器( IE桌面Chrome )中如预期的那样工作，但是

它在旧的浏览器中不起作用。在较旧的浏览器(例如iOS 8)中，我得到以下错误：

SyntaxError: Unexpected token ')'

指向本机shim中的开放匿名函数：

(() => {
  'use strict';

  // Do nothing if `customElements` does not exist.
  if (!window.customElements) return;

  const NativeHTMLElement = window.HTMLElement;
  const nativeDefine = window.customElements.define;
  const nativeGet = window.customElements.get;

因此，在我看来，native-shim似乎需要转移到ES5上：

        include: [
+         path.join(NODE_MODULES_DIR, '@webcomponents/custom-elements/src/native-shim'),
          path.join(NODE_MODULES_DIR, '<module that uses CustomElements>'),
          path.join(__dirname, '../src'),
        ],

...but这样做现在破坏了Chrome和iOS 8，并出现了以下错误：

app.js:1 Uncaught TypeError: Failed to construct 'HTMLElement': Please use the 'new' operator, this DOM object constructor cannot be called as a function.
    at new StandInElement (native-shim.js:122)
    at HTMLDocument.createElement (<anonymous>:1:1545)
    at ReactDOMComponent.mountComponent (ReactDOMComponent.js:504)
    at Object.mountComponent (ReactReconciler.js:46)
    at ReactCompositeComponentWrapper.performInitialMount (ReactCompositeComponent.js:371)
    at ReactCompositeComponentWrapper.mountComponent (ReactCompositeComponent.js:258)
    at Object.mountComponent (ReactReconciler.js:46)
    at Object.updateChildren (ReactChildReconciler.js:121)
    at ReactDOMComponent._reconcilerUpdateChildren (ReactMultiChild.js:208)
    at ReactDOMComponent._updateChildren (ReactMultiChild.js:312)

。。这就引出了本机shim中的constructor()行：

  window.customElements.define = (tagname, elementClass) => {
    const elementProto = elementClass.prototype;
    const StandInElement = class extends NativeHTMLElement {
      constructor() {

呼。因此，我非常不清楚我们是如何将其包含在基于webpack的构建中的，在该构建中，使用CustomElements的依赖项是ES6 (并且需要转换)。

• 将本机-shim转换为es5不起作用。
• 在包入口点顶部使用本机shim is不适用于iOS 8，但对Chrome有效。
• 不包括原生shim破坏了Chrome和iOS。

在这一点上，我对web组件感到非常沮丧。我只想使用这个依赖关系，它恰好是用web组件构建的。我怎样才能让它在webpack的建筑中正常工作，并在所有的设备上工作呢？我是不是漏掉了什么明显的东西？

为了后代而我的.babelrc配置(最相关的.babelrc配置)：

{
  "presets": [
    ["es2015", { "modules": false }],
    "react"
  ],
  "plugins": [
    "transform-custom-element-classes",
    "transform-object-rest-spread",
    "transform-object-assign",
    "transform-exponentiation-operator"
  ],
  "env": {
    "test": {
      "plugins": [
        [ "babel-plugin-webpack-alias", { "config": "./cfg/test.js" } ]
      ]
    },
    "dev": {
      "plugins": [
        "react-hot-loader/babel",
        [ "babel-plugin-webpack-alias", { "config": "./cfg/dev.js" } ]
      ]
    },
    "dist": {
      "plugins": [
        [ "babel-plugin-webpack-alias", { "config": "./cfg/dist.js" } ],
        "transform-react-constant-elements",
        "transform-react-remove-prop-types",
        "minify-dead-code-elimination",
        "minify-constant-folding"
      ]
    },
    "production": {
      "plugins": [
        [ "babel-plugin-webpack-alias", { "config": "./cfg/server.js" } ],
        "transform-react-constant-elements",
        "transform-react-remove-prop-types",
        "minify-dead-code-elimination",
        "minify-constant-folding"
      ]
    }
  }
}

Answer 1

我能够在下面的.babelrc插件管道中实现类似的功能。看起来唯一的区别是https://babeljs.io/docs/plugins/transform-es2015-classes/和https://babeljs.io/docs/plugins/transform-es2015-classes/，但我真的不记得他们具体解决了哪些问题：

{
  "plugins": [
    "transform-runtime",
    ["babel-plugin-transform-builtin-extend", {
      "globals": ["Error", "Array"]
    }],
    "syntax-async-functions",
    "transform-async-to-generator",
    "transform-custom-element-classes",
    "transform-es2015-classes"
  ]
}