webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  entry: ['babel-polyfill', './src/index.js'],
  output: {
    path: path.join(__dirname, '/dist'), filename: 'index.js'
  },
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        exclude: /node_modules/,
        loader: 'babel-loader',
        options: {
          presets: [
            '@babel/preset-env',
            '@babel/preset-react',
            {
              plugins: ['@babel/plugin-proposal-class-properties']
            }
          ]
        }
      },
      {
        test: /\.(css|scss)$/,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader',
          {
            loader: 'sass-resources-loader',
            options: {
              resources: ['src/styles/styles.scss']
            }
          }
        ]
      }
    ]
  },
  plugins: [
    new HtmlWebpackPlugin({
      inject: true,
      template: './public/index.html',
    }),
  ]
};