old_contents: const webpack = require('webpack');
  
  const webpackConfig = require('./conf.common');
  const moduleConfigDev = require('./module.dev');
  
  module.exports = Object.assign({}, webpackConfig, {
      devtool: 'source-map',
      entry: [
          `webpack-dev-server/client?http://0.0.0.0:${process.env.PORT_WDS}`,
          'webpack/hot/only-dev-server'
      ].concat(webpackConfig.entry),
      plugins: webpackConfig.plugins.concat([
          new webpack.HotModuleReplacementPlugin()
      ]),
      module: moduleConfigDev,
      devServer: {
          stats: {
              colors: true,
              modules: false,
              chunks: false,
              reasons: true
          },
          hot: true,
          quiet: false,
          noInfo: false,
          publicPath: '/',
          port: process.env.PORT_WDS,
          proxy: {
              '/': {
                  target: `http://localhost:${process.env.PORT}`,
                  secure: false
              }
          }
      }
  });
  
  
new_contents: const webpack = require('webpack');
  
  const webpackConfig = require('./conf.common');
  const moduleConfigDev = require('./module.dev');
  
  module.exports = Object.assign({}, webpackConfig, {
      devtool: 'source-map',
      entry: [
          `webpack-dev-server/client?http://0.0.0.0:${process.env.PORT_WDS}`,
          'webpack/hot/only-dev-server'
      ].concat(webpackConfig.entry),
      plugins: webpackConfig.plugins.concat([
          new webpack.DefinePlugin({
              'process.env': {
                  NODE_ENV: JSON.stringify('development')
              }
          }),
          new webpack.HotModuleReplacementPlugin()
      ]),
      module: moduleConfigDev,
      devServer: {
          stats: {
              colors: true,
              modules: false,
              chunks: false,
              reasons: true
          },
          hot: true,
          quiet: false,
          noInfo: false,
          publicPath: '/',
          port: process.env.PORT_WDS,
          proxy: {
              '/': {
                  target: `http://localhost:${process.env.PORT}`,
                  secure: false
              }
          }
      }
  });
  
  
subject: Insert development node env into webpack