webpack.config.js

const path = require('path');

module.exports = {
  devtool: 'source-map',
  output: {
    filename: 'react-app.js'
  },
  devServer: {
    static: {
      directory: path.join(__dirname, 'public'),
    },
    compress: true,
    port: 9000,
    headers: {
      "Access-Control-Allow-Origin": "http://localhost:8000",
      "Access-Control-Allow-Credentials": "true",
      "Access-Control-Allow-Headers": "Content-Type, Authorization, x-id, Content-Length, X-Requested-With",
      "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE, OPTIONS"
    }
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        loader: "babel-loader",
        options: {
          presets: ['@babel/preset-env', '@babel/preset-react']
        }
      },
      {
        test: /\.css$/,
        use: [
          'style-loader',
          'css-loader'
        ]
      }
    ]

  },
  resolve: {
    extensions: ['.js', '.jsx']
  }
};