由于 ES6 的扩展语法，Webpack 和 Babel 没有在 node_modules 内转译依赖项，这会破坏 IE 11 和 Edge

Question

我有一个使用 @mdx-js/runtime 的项目，它在 IE 11 或 Edge (Edge 44.18362.449.0) 上完全崩溃：

SCRIPT1028: SCRIPT1028: Expected identifier, string or number

它实际上因为这里的传播语法而中断：

const allNodes = sortedNodes.map(({ start: _, ...node }, i) => {

这行代码来自 remark-mdx，它是 @mdx-js/runtime 的依赖项，特别是这个文件和行：https://github.com/mdx-js/mdx/blob/master/packages/remark-mdx/extract-imports-and-exports.js#L66

我一直在尝试让 Webpack 和 Babel 转换该文件，以便传播不再存在：

浏览器列表：

如果我运行 npx browserslist 我可以看到 IE 11 在那里。

"browserslist": [
    "> 0.5%",
    "last 2 version",
    "Firefox ESR",
    "not dead",
    "iOS >= 9"
]

.babelrc:

我试过禁用 loose 模式并添加 @babel/plugin-transform-spread 和 @babel/plugin-proposal-object-rest-spread，但没有解决问题。

  {
    "presets": [[
        "@babel/preset-env", {
            "useBuiltIns": "usage",
            "loose": false, // Was true before
            "modules": "auto",
            "corejs": 3
        }],
        "@babel/preset-react",
        "@babel/preset-typescript"
    ],

    "plugins": [
        ["@babel/plugin-proposal-decorators", {
            "legacy": true
        }],
        ["@babel/plugin-proposal-class-properties", {
            "loose": true
        }],
        "@babel/plugin-transform-spread", // Just added
        "@babel/plugin-proposal-object-rest-spread", // Just added
        "@babel/plugin-proposal-optional-chaining",
        "@babel/plugin-proposal-nullish-coalescing-operator",
        "react-hot-loader/babel"
    ]
}

webpack.config.js:

我在这里尝试明确包括 remark-mdx 和 @mdx-js/runtime 并删除 exclude 属性或将其更改为 /node_modules\/(?!(remark-mdx|@mdx-js\/runtime)\/).*/，但似乎没有任何效果:

  {
    test: /\.(j|t)sx?$/,
    include: [
      path.resolve(__dirname, 'src'),
      // Tried explicitly adding these 2:
      path.resolve('node_modules/remark-mdx'),
      path.resolve('node_modules/@mdx-js/runtime'),
    ],
    // Tried removing `exclude` or not excluding those 2 packages:
    // exclude: /node_modules/,
    // exclude: /node_modules\/(?!(remark-mdx|@mdx-js\/runtime)\/).*/,
    use: [{
      loader: 'babel-loader',
      options: {
        cacheDirectory: true,
        babelrc: true,
      }
    }],
  }

我正在使用 Babel 7 和 Webpack 4。

Answer 1

好的，事实证明要处理 node_modules 中的文件，您需要使用 babel.config.js 而不是 .babelrc，如 here and here:

所述

What's your use case?

You are using a monorepo?

You want to compile node_modules?

babel.config.json is for you!

You have a configuration that only applies to a single part of your project?

.babelrc.json is for you!

此外，如果您使用的是 monorepo，则需要设置 rootMode: 'upward' so that Babel can find your new config file, as explained here。

Webpack 的 babel-loader 配置应如下所示：

  {
    test: /\.(j|t)sx?$/,
    include: [
      path.resolve(__dirname, 'src'),
      // No need to add @mdx-js/runtime, just add the problematic package:
      path.resolve('node_modules/remark-mdx'),
    ],
    // You also need to exclude it from the exclusions:
    exclude: /node_modules\/(?!(remark-mdx)\/).*/,
    use: [{
      loader: 'babel-loader',
      options: {
        cacheDirectory: true,
        // And replace .babelrc with babel.config.json...
        babelrc: false,
        // ...which might also mean you need this if you are using a monorepo:
        rootMode: 'upward',
      }
    }],
  }

此更改后正在处理文件，但出现了不同的错误：

Uncaught TypeError: Cannot assign to read only property 'exports' of object '#<Object>'

在这种情况下，我必须添加 sourceType: "unambiguous" to babel.config.json, as remark-mdx was using CommonJS modules rather than ES6 ones. You can add this at the root of your babel.config.json file or inside overrides，以便它只针对 node_modules.

内的包

有关发生这种情况的原因的更多信息，请参阅。

Babel 的 babel.config.json 最终看起来像这样：

{
    "presets": [[
        "@babel/preset-env", {
            "useBuiltIns": "usage",
            "loose": true,
            "modules": "auto",
            "corejs": 3
        }],
        "@babel/preset-react",
        "@babel/preset-typescript"
    ],

    "plugins": [
        ["@babel/plugin-proposal-decorators", {
            "legacy": true
        }],
        ["@babel/plugin-proposal-class-properties", {
            "loose": true
        }],
        "@babel/plugin-proposal-optional-chaining",
        "@babel/plugin-proposal-nullish-coalescing-operator",
        "react-hot-loader/babel"
    ],

    "overrides": [{
        "test": "./node_modules",
        "sourceType": "unambiguous"
    }]
}

由于 ES6 的扩展语法，Webpack 和 Babel 没有在 node_modules 内转译依赖项，这会破坏 IE 11 和 Edge

Webpack and Babel not transpiling a dependency inside node_modules that breaks IE 11 and Edge due to ES6's spread syntax

ecmascript-6

webpack

babeljs

es6-modules

babel-loader