webpack.config.js

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


module.exports = {
  mode: 'development',
  devtool: 'cheap-module-source-map',

  entry: ['react-dev-utils/webpackHotDevClient', path.resolve('src/index.js')],

  resolve: {
    modules: [
      path.resolve('src'),
      path.resolve('node_modules'),
    ],
    extensions: ['.js', '.jsx'],
  },

  output: {
    path: path.resolve('.tmp'),
    filename: '[name].js',
    publicPath: '/',
  },

  plugins: [
    new webpack.HotModuleReplacementPlugin(),
    new HTMLWebpackPlugin({
      template: path.resolve('public/index.html'),
    }),
  ],

  devServer: {
    contentBase: '.tmp',
    hot: true,
    port: 3000,
  },

  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            cacheDirectory: true,
            plugins: ['react-hot-loader/babel'],
          },
        },
      },
      {
        test: /\.(scss|sass)$/,
        use: [
          { loader: 'style-loader' },
          {
            loader: 'css-loader',
            options: {
              sourceMap: true,
            },
          },
          {
            loader: 'postcss-loader',
            options: {
              sourceMap: true,
              plugins: () => [
                autoprefixer({
                  browsers: [
                    '>1%',
                    'last 4 versions',
                    'Firefox ESR',
                    'not ie < 10',
                  ],
                }),
              ],
            },
          },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: true,
            },
          },
        ],
      },
      {
        test: /\.(jpe?g|png|gif|ico)$/i,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: '[name].[ext]',
            },
          },
        ],
      },
    ],
  },
};