Upgrade webpack to v4

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Webpack Plugin

splitChunk:

• https://juejin.im/post/5af1677c6fb9a07ab508dabb
• https://webpack.js.org/configuration/optimization/#optimization-splitchunks

webpack 基础知识

1. contenthash, hash, chunkhash 之间的不同：

• What is the difference between hash, chunkhash and contenthash? webpack-contrib/extract-text-webpack-plugin#153
• https://stackoverflow.com/questions/35176489/what-is-the-purpose-of-webpack-hash-and-chunkhash/52786672#52786672

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Babel

babel 基础知识

1. babel，babel-core， babel-loader， babel-preset-2015， babel-preset-react， babel-polyfill：https://stackoverflow.com/a/48516794/9617320

babel 7.2

2. @babel/core vs babel-core: https://stackoverflow.com/a/53395718/9617320
3. @babel/polyfill vs @babel/plugin-transform-runtime:

• https://stackoverflow.com/a/47326735/9617320
• https://juejin.im/post/5a96859a6fb9a063523e2591
• https://stackoverflow.com/a/48516794/9617320

+@babel/plugin-proposal-class-properties

Support for the experimental syntax 'classProperties' isn't currently enabled

see babel/babel#8655

+@babel/plugin-proposal-export-default-from

Support for the experimental syntax 'exportDefaultFrom' isn't currently enabled

see babel/babel#7293

🔼babel-eslint: https://github.com/babel/babel-eslint

allow function is no-defined

⚠️注意

• babel-loader config 与 .babelrc 之间是互斥的

babel 7.1

Support for the experimental syntax 'exportDefaultFrom' isn't currently enabled

babel-preset-stage-1 中内置了这个功能，但 babel-preset-env 中没有，但直接安装 babel-plugin-transform-export-extensions 却报 404, 所以通过安装 babel-preset-stage-1 来进行安装, see https://stackoverflow.com/a/41058960/9617320

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Eslint

🔼 eslint-loader: https://github.com/webpack-contrib/eslint-loader/releases/tag/2.0.0
🔼 eslint@4.9.0
🔼 eslint-plugin-react@7.4.0
🔼 eslint-plugin-import@2.7.0
🔼 eslint-plugin-jsx-a11y@6.0.2

其他

• 查看依赖的 peerDependencies 版本：

   npm info "eslint-config-airbnb@16.0.0" peerDependencies

 { 
   eslint: '^4.9.0',
  'eslint-plugin-jsx-a11y': '^6.0.2',
  'eslint-plugin-import': '^2.7.0',
  'eslint-plugin-react': '^7.4.0' 
}