npm install -g create-react-app

npx create-react-app my-app

┌─node_modules 
├─public
├─src      
├─.gitignore
├─package.json
├─README.md
└─yarn.lock

yarn add less less-loader

λ yarn eject
yarn run v1.6.0
$ react-scripts eject
? Are you sure you want to eject? This action is permanent. Yes
Ejecting...

Copying files into E:\React\my-app
 Adding \config\env.js to the project
 Adding \config\paths.js to the project
 Adding \config\polyfills.js to the project
 Adding \config\webpack.config.dev.js to the project
 Adding \config\webpack.config.prod.js to the project
 Adding \config\webpackDevServer.config.js to the project
 Adding \config\jest\cssTransform.js to the project
 Adding \config\jest\fileTransform.js to the project
 Adding \scripts\build.js to the project
 Adding \scripts\start.js to the project
 Adding \scripts\test.js to the project

Updating the dependencies
 Removing react-scripts from dependencies
 Adding autoprefixer to dependencies
 Adding babel-core to dependencies
 Adding babel-eslint to dependencies
 Adding babel-jest to dependencies
 Adding babel-loader to dependencies
 Adding babel-preset-react-app to dependencies
 Adding babel-runtime to dependencies
 Adding case-sensitive-paths-webpack-plugin to dependencies
 Adding chalk to dependencies
 Adding css-loader to dependencies
 Adding dotenv to dependencies
 Adding dotenv-expand to dependencies
 Adding eslint to dependencies
 Adding eslint-config-react-app to dependencies
 Adding eslint-loader to dependencies
 Adding eslint-plugin-flowtype to dependencies
 Adding eslint-plugin-import to dependencies
 Adding eslint-plugin-jsx-a11y to dependencies
 Adding eslint-plugin-react to dependencies
 Adding extract-text-webpack-plugin to dependencies
 Adding file-loader to dependencies
 Adding fs-extra to dependencies
 Adding html-webpack-plugin to dependencies
 Adding jest to dependencies
 Adding object-assign to dependencies
 Adding postcss-flexbugs-fixes to dependencies
 Adding postcss-loader to dependencies
 Adding promise to dependencies
 Adding raf to dependencies
 Adding react-dev-utils to dependencies
 Adding resolve to dependencies
 Adding style-loader to dependencies
 Adding sw-precache-webpack-plugin to dependencies
 Adding url-loader to dependencies
 Adding webpack to dependencies
 Adding webpack-dev-server to dependencies
 Adding webpack-manifest-plugin to dependencies
 Adding whatwg-fetch to dependencies

Updating the scripts
 Replacing "react-scripts start" with "node scripts/start.js"
 Replacing "react-scripts build" with "node scripts/build.js"
 Replacing "react-scripts test" with "node scripts/test.js"

Configuring package.json
 Adding Jest configuration
 Adding Babel preset
 Adding ESLint configuration

Ejected successfully!

Please consider sharing why you ejected in this survey:
 http://goo.gl/forms/Bi6CZjk1EqsdelXk1

Done in 5.37s.

webpack.config.dev.js    # 開發(fā)環(huán)境配置
webpack.config.prod.js   # 生產(chǎn)環(huán)境配置
webpackDevServer.config.js # 開發(fā)服務(wù)器配置

// "postcss" loader applies autoprefixer to our CSS.
// "css" loader resolves paths in CSS and adds assets as dependencies.
// "style" loader turns CSS into JS modules that inject <style> tags.
// In production, we use a plugin to extract that CSS to a file, but
// in development "style" loader enables hot editing of CSS.
{
 test: /\.(css|less)$/,
 use: [
  require.resolve('style-loader'),
  {
   loader: require.resolve('css-loader'),
   options: {
    importLoaders: 1,
   },
  },
  {
   loader: require.resolve('postcss-loader'),
   options: {
    // Necessary for external CSS imports to work
    // https://github.com/facebookincubator/create-react-app/issues/2677
    ident: 'postcss',
    plugins: () => [
     require('postcss-flexbugs-fixes'),
     autoprefixer({
      browsers: [
       '>1%',
       'last 4 versions',
       'Firefox ESR',
       'not ie < 9', // React doesn't support IE8 anyway
      ],
      flexbox: 'no-2009',
     }),
    ],
   },
  },
  {
   loader: require.resolve('less-loader')
  }
 ],
},

@title-color:#f00;

.App-title {
  color: @title-color
 }

import './Test.less';