webpack4配置详解

//方式一：单文件写法
entry: {
	index: './src/pages/route.js',
	//about: './src/pages/about.js',
	//other:()=>{...}
}

//方式二：多文件写法
entry: {
	/*index:[
		'webpack-hot-middleware/client',
		'./src/root.js'
	],*/
	index: ['./src/root.js'],
	vendors : ['react','react-dom','redux','react-router','classnames'],
}

output: {
	path: path.resolve(__dirname, '../assets'),
	filename: 'js/[name].js',
	chunkFilename: 'js/[name].[chunkhash:8].js',
	publicPath: '/_static_/', //最终访问的路径就是：localhost:3000/_static_/js/*.js
	//pathinfo:true,
}

//方法一
webpack --mode development/production

//方法二
……
mode:'development/production'
……

//环境变更也可以直接 在启动中设置
 //webpack --env.NODE_ENV=local --env.production --progress

//splitChunks 默认配置
splitChunks: {
  chunks: 'async',
  minSize: 30000,
  maxSize: 0,
  minChunks: 1,
  maxAsyncRequests: 5,
  maxInitialRequests: 3,
  automaticNameDelimiter: '~',
  name: true,
  cacheGroups: {
    vendors: {
      test: /[\\/]node_modules[\\/]/,
      priority: -10
    },
    default: {
      minChunks: 2,
      priority: -20,
      reuseExistingChunk: true
    }
  }
}

optimization: {
	runtimeChunk:true,//方式一
  runtimeChunk: {
    name: entrypoint => `runtimechunk~${entrypoint.name}` //方式二
  }
}

//extensions 后缀可以省略，
import Toast from 'src/components/toast'; 

// alias ,短路径
import Modal from '../../../components/modal' 
//简写
import Modal from 'src/components/modal' 


resolve: {
  extensions: ['.js', '.jsx','.ts','.tsx', '.scss','.json','.css'],
  alias: {
    src :path.resolve(__dirname, '../src'),
    components :path.resolve(__dirname, '../src/components'),
    utils :path.resolve(__dirname, '../src/utils'),
  },
  modules: ['node_modules'],
},

module: {
	rules: [
		{
			test: /\.(js|jsx)$/,
			exclude: /node_modules/,
			use: [
				{
					loader: 'babel-loader',
					options: {
						presets: [
							['env',
							{
								targets: {
								browsers: CSS_BROWSERS,
							},
						}],'react', 'es2015', 'stage-0'
						],
						plugins: [
							'transform-runtime',
							'add-module-exports',
						],
					},
				},
			],
		},
		{
			test: /\.(scss|css)$/,
			use: [
				'style-loader',
				{loader: 'css-loader',options:{plugins: [require('autoprefixer')({browsers: CSS_BROWSERS,}),],sourceMap: true}},
				{loader: 'postcss-loader',options:{plugins: [require('autoprefixer')({browsers: CSS_BROWSERS,}),],sourceMap: true}},
				{loader: 'sass-loader',options:{sourceMap: true}}
			]
		},
		{
			test: /\.(png|jpg|jpeg|gif)$/,
			exclude: /node_modules/,
			use: [
				{
					loader: 'url-loader?limit=12&name=images/[name].[hash:8].[ext]',
				},
			],
		},
		{
			test: /\.(woff|woff2|ttf|eot|svg)$/,
			exclude: /node_modules/,
			use: [
				{
					loader: 'file-loader?name=fonts/[name].[hash:8].[ext]',
				},
			],
		},
	],
},