webpack.config.dev.js

const merge = require('webpack-merge');
const path = require('path');
const webpack = require('webpack');

const common = require('./webpack.config.common');

module.exports = merge(common, {
  mode: 'development',
  devtool: 'eval',
  devServer: {
    contentBase: path.join(__dirname, 'public'),
    compress: true,
    hot: true,
    open: true,
  },
  entry: [
    'webpack-hot-middleware/client?path=http://localhost:3000/__webpack_hmr',
    './client/src/index.js',
  ],
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [
          {
            loader: 'style-loader',
          },
          {
            loader: 'css-loader',
            options: {
              sourceMap: true,
            },
          },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: true,
            },
          },
        ],
      },
      {
        test: /\.html$/,
        use: [
          {
            loader: 'html-loader',
            options: {},
          },
        ],
      },
    ],
  },
  plugins: [new webpack.HotModuleReplacementPlugin()],
});