解决vue热替换失效的根本原因

 env: require('./dev.env'),
 port: 8080,
 autoOpenBrowser: true,
 assetsSubDirectory: 'static',//必须
 assetsPublicPath: '/',

http://localhost:8080/__webpack_hmr net::ERR_INCOMPLETE_CHUNKED_ENCODING

// webpack编译输出的发布路径
// => 将 build 的路径前缀修改为 ' ./ '（原本为 ' / '），是因为打包(npm run build)之后，
// 外部引入 js 和 css 文件时，如果路径以 ' / ' 开头，在本地是无法找到对应文件的（服务器上没问题）

module.exports = {
 build: {
 env: require('./prod.env'),
 index: path.resolve(__dirname, '../dist/index.html'),
 assetsRoot: path.resolve(__dirname, '../dist'),
 assetsSubDirectory: 'static',
 assetsPublicPath: './',
 productionSourceMap: true,
 // Gzip off by default as many popular static hosts such as
 // Surge or Netlify already gzip all static assets for you.
 // Before setting to `true`, make sure to:
 // npm install --save-dev compression-webpack-plugin
 productionGzip: false,
 productionGzipExtensions: ['js', 'css'],
 // Run the build command with an extra argument to
 // View the bundle analyzer report after build finishes:
 // `npm run build --report`
 // Set to `true` or `false` to always turn it on or off
 bundleAnalyzerReport: process.env.npm_config_report
 },
 dev: {
 env: require('./dev.env'),
 port: 8081,
 autoOpenBrowser: true,
 assetsSubDirectory: 'static',
 assetsPublicPath: '/',
 proxyTable: {},
 // CSS Sourcemaps off by default because relative paths are "buggy"
 // with this option, according to the CSS-Loader README
 // (https://github.com/webpack/css-loader#sourcemaps)
 // In our experience, they generally work as expected,
 // just be aware of this issue when enabling this option.
 cssSourceMap: true
 }