zoro-cli/lib/plugins/config-webpack/template/script/config/dev.js

https://github.com/vuejs/vue-cli

module.exports = ({ api, options, envUtil, args }) => {
  api.chainWebpack(webpackConfig => {
    if (envUtil.isDevelopment()) {
      webpackConfig.mode('development')

      if (args.nodevtool || !options.devtool) {
        webpackConfig.devtool(false)
      } else {
        let { devtool } = options
        devtool =
          typeof devtool === 'string' ? devtool : 'cheap-module-eval-source-map'
        webpackConfig.devtool(devtool)
      }

      webpackConfig.output.publicPath('/').pathinfo(true)

      if (args.nohmr) {
        // no hmr when see
      } else {
        webpackConfig
          .plugin('hmr')
          .use(require('webpack/lib/HotModuleReplacementPlugin'))
      }

      // webpack Enables NamedChunksPlugin and NamedModulesPlugin when mode === 'development'.

      webpackConfig
        .plugin('no-emit-on-errors')
        .use(require('webpack/lib/NoEmitOnErrorsPlugin'))

      // allow disable serve progress via devServer.progress
      if (options.devServer.progress !== false) {
        webpackConfig
          .plugin('progress')
          .use(require('webpack/lib/ProgressPlugin'))
      }
    }
  })
}