webpack.dev.js

const path = require('path');
// eslint-disable-next-line import/no-extraneous-dependencies
const HtmlWebpackPlugin = require('html-webpack-plugin');
// eslint-disable-next-line import/no-extraneous-dependencies
const ESLintPlugin = require('eslint-webpack-plugin');

module.exports = {
  mode: 'development',
  entry: {
    main: './src/index.js',
  },
  devtool: 'eval-source-map',
  output: {
    filename: '[name].bundle.js',
    path: path.resolve(__dirname, 'dist'),
  },
  devServer: {
    contentBase: path.join(__dirname, 'dist'),
    compress: false,
    port: 3001,
    hot: true,
    open: true,
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: './src/index.html',
    }),
    new ESLintPlugin({
      extensions: ['js', 'sass'],
      fix: true,
    }),
  ],
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader',
        ],
      },
      {
        test: /\.js$/,
        exclude: /(node_modules|bower_components)/,
        use: [
          {
            loader: 'babel-loader',
            options: {
              presets: [
                '@babel/preset-env',
                '@babel/preset-react',
              ],
              plugins: ['@babel/plugin-transform-runtime'],
            },
          },
        ],
      },
    ],
  },
};