const webpack = require('webpack'); const merge = require('webpack-merge'); const common = require('./webpack.config.common.js'); module.exports = merge(common, { mode: 'development', devServer: { contentBase: 'src', watchContentBase: true, hot: true, open: true, port: process.env.PORT || 9000, host: process.env.HOST || 'localhost', }, module: { rules: [ { test: /\.(sass|scss)$/, use: ['style-loader', 'css-loader', 'postcss-loader', 'sass-loader'], }, ], }, plugins: [new webpack.HotModuleReplacementPlugin()], });