webpack.config.js

const path = require('path');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');

module.exports = (env, options) => ({
  optimization: {
    minimizer: [
      new UglifyJsPlugin({ cache: true, parallel: true, sourceMap: false }),
      new OptimizeCSSAssetsPlugin({}),
    ],
  },
  entry: {
    app: [
      'webpack/hot/only-dev-server',
      './assets/css/app.scss',
      './assets/src/app.tsx',
    ],
  },

  output: {
    filename: 'app.js',
    path: path.resolve(__dirname, 'priv/static/js'),
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx|ts|tsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
        },
      },
      {
        test: /\.(css|sass|scss)$/,
        use: [
          MiniCssExtractPlugin.loader,
          {
            loader: 'css-loader',
            options: {
              importLoaders: 2,
              sourceMap: true,
            },
          },
          {
            loader: 'postcss-loader',
            options: {
              plugins: () => [require('autoprefixer')],
              sourceMap: true,
            },
          },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: true,
            },
          },
        ],
      },
      {
        test: /\.(woff(2)?|ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: '[name].[ext]',
              outputPath: '../fonts',
            },
          },
        ],
      },
    ],
  },
  plugins: [
    new MiniCssExtractPlugin({ filename: '../css/app.css' }),
    new CopyWebpackPlugin([{ from: 'assets/static/', to: '../' }]),
  ],
  resolve: {
    extensions: ['.ts', '.tsx', '.js', '.jsx', '.json', '.scss'],
  },
});