webpack.config.dev.js

import webpack from 'webpack';
import path from 'path';

export default {
  mode: "development", // "production" | "development" | "none"
  devtool: 'cheap-module-eval-source-map',
  entry: [
    'eventsource-polyfill', // necessary for hot reloading with IE
    'webpack-hot-middleware/client?reload=true', //note that it reloads the page if hot module reloading fails.
    path.resolve(__dirname, 'src/index')
  ],
  target: 'web', // Bundle application to run on browser
  output: { 
    path: __dirname + '/dist', // Note: Physical files are only output by the production build task `npm run build`.
    publicPath: '/',
    filename: 'bundle.js'
  },
  devServer: {
    contentBase: path.resolve(__dirname, 'src'),
    watchContentBase: true,
    hot: true
  },
  plugins: [
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NoEmitOnErrorsPlugin()
  ],
  module: {
    rules: [
      {
        test: /\.js$/,
        use: 'babel-loader',
        exclude: /node_modules/
        /* test: /\.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/,
        options: {
          presets: ['react', 'es2015', 'react-hmre'],
          plugins: ['transform-class-properties']
        } */
      },
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader']
      },
      {
        test: /\.(woff(2)?|ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
        use: [{
            loader: 'file-loader',
            options: {
                name: '[name].[ext]',
                outputPath: 'fonts/'
            }
        }]
    }
    ]
  },
  performance: {
    maxEntrypointSize: 400000,
    maxAssetSize: 100000
  }
};