webpack.config.js

const webpack = require('webpack');
const path = require('path');

// variables
const isProduction = process.argv.indexOf('-p') >= 0 || process.env.NODE_ENV === 'production';
const sourcePath = path.join(__dirname, './src');
const outPath = path.join(__dirname, './dist');

// plugins
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const WebpackCleanupPlugin = require('webpack-cleanup-plugin');
const dotenv = require('dotenv');

// call dotenv and it will return an Object with a parsed key
const env = dotenv.config().parsed;

// reduce it to a nice object, the same as before
const envKeys = Object.keys(env).reduce((prev, next) => {
  prev[`process.env.${next}`] = JSON.stringify(env[next]);
return prev;
}, {});

module.exports = {
  context: sourcePath,
  entry: {
    app: [
        './main.tsx',
        './assets/sass/style.scss'
      ]
  },
  output: {
    path: outPath,
    filename: 'js/bundle-[hash].js',
    chunkFilename: 'js/[chunkhash].js',
    publicPath: '/'
  },
  target: 'web',
  resolve: {
    extensions: ['.js', '.ts', '.tsx'],
    // Fix webpack's default behavior to not load packages with jsnext:main module
    // (jsnext:main directs not usually distributable es6 format, but es6 sources)
    mainFields: ['module', 'browser', 'main'],
    alias: {
      app: path.resolve(__dirname, 'src/app/')
    }
  },
  module: {
    rules: [
      // .ts, .tsx
      {
        test: /\.tsx?$/,
        use: [
          !isProduction && {
            loader: 'babel-loader',
            options: { plugins: ['react-hot-loader/babel'] }
          },
          'ts-loader'
        ].filter(Boolean)
      },
      {
        test: /\.scss$/,
        use: [
          isProduction ? MiniCssExtractPlugin.loader : 'style-loader',
          'css-loader',
          'sass-loader'
          ]
      },
      // static assets
      { test: /\.html$/, use: 'html-loader' },
      { test: /\.(a?png|svg)$/, use: 'url-loader?limit=10000' },
      { test: /\.(jpe?g|gif|bmp|mp3|mp4|ogg|wav|eot|ttf|woff|woff2)$/, use: 'file-loader' }
    ]
  },
  optimization: {
    splitChunks: {
      name: true,
      cacheGroups: {
        commons: {
          chunks: 'initial',
          minChunks: 2
        },
        vendors: {
          test: /[\\/]node_modules[\\/]/,
          chunks: 'all',
          priority: -10
        }
      }
    },
    runtimeChunk: true
  },
  plugins: [
    new webpack.EnvironmentPlugin({
      NODE_ENV: 'development', // use 'development' unless process.env.NODE_ENV is defined
      DEBUG: false
    }),
    new WebpackCleanupPlugin(),
    new MiniCssExtractPlugin({
      filename: 'css/style-[contenthash].css',
      disable: !isProduction
    }),
    new HtmlWebpackPlugin({
      template: 'assets/index.html'
    }),
    new webpack.DefinePlugin(envKeys)
  ],
  devServer: {
    contentBase: sourcePath,
    hot: true,
    inline: true,
    historyApiFallback: {
      disableDotRule: true
    },
    stats: 'minimal',
    clientLogLevel: 'warning'
  },
  // https://webpack.js.org/configuration/devtool/
  devtool: isProduction ? '' : 'eval-source-map',
  node: {
    // workaround for webpack-dev-server issue
    // https://github.com/webpack/webpack-dev-server/issues/60#issuecomment-103411179
    fs: 'empty',
    net: 'empty'
  }
};