webpack.config.js

const webpack = require('webpack');
const { resolve } = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const Dotenv = require('dotenv-webpack');

module.exports = {

  entry: [
    'react-hot-loader/patch',
    'webpack-dev-server/client?http://localhost:8080',
    'webpack/hot/only-dev-server',
    resolve(__dirname, "src", "index.jsx")
  ],

  output: {
    filename: 'app.bundle.js',
    path: resolve(__dirname, 'build'),
    publicPath: '/'
  },

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

  devtool: '#source-map',

  devServer: {
    hot: true,
    contentBase: resolve(__dirname, 'build'),
    publicPath: '/'
  },

  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
            'style-loader',
            'css-loader'
        ]
      },
      {
        test: /\.jsx?$/,
        loader: "babel-loader",
        exclude: /node_modules/,
        options: {
          presets: [
            ["es2015", {"modules": false}],
            "react",
          ],
          plugins: [
            "react-hot-loader/babel",
            'transform-object-rest-spread'
          ]
        }
      },
      {
        test: /\.(jpe?g|png|gif|svg)$/i,
        loader: 'file-loader'
      },
      {
        test: /\.mp3$/,
        loader: 'file-loader'
      },
    ]
  },

  plugins: [
      new webpack.HotModuleReplacementPlugin(),
      new webpack.NamedModulesPlugin(),
      new HtmlWebpackPlugin({
        template:'template.ejs',
        appMountId: 'react-app-root',
        title: 'PomoDogo',
        filename: resolve(__dirname, "build", "index.html"),
      }),
      new Dotenv(),
    ]
  };