webpack.config.babel.js

import path from "path";
import webpack from "webpack";
import CaseSensitivePathsPlugin from "case-sensitive-paths-webpack-plugin";
import CircularDependencyPlugin from "circular-dependency-plugin";
import DuplicatePackageCheckerPlugin from "duplicate-package-checker-webpack-plugin";
import HappyPack from "happypack";
import TerserPlugin from "terser-webpack-plugin";

const NODE_ENV = process.env.NODE_ENV ? "production" : "development";
const isDevelopment = NODE_ENV === "development";

const options = {
  mode: NODE_ENV,
  entry: "./main.js",
  output: {
    filename: "[name].js",
    path: path.join(__dirname, "/dest/assets/javascripts"),
    publicPath: "/assets/javascripts/",
    library: "App",
  },
  resolve: {
    modules: ["node_modules", path.join(__dirname, "soruce")],
    alias: {
      "lodash-es": "lodash",
      "@": path.resolve(__dirname, "source"),
    },
  },
  devtool: isDevelopment ? "eval-source-map" : "source-map",
  context: path.resolve(__dirname, "source/scripts"),
  optimization: {
    minimize: !isDevelopment,
    minimizer: [new TerserPlugin()],
  },
  module: {
    noParse: /\/node_modules\/(jquery|backbone)/,
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: "happypack/loader",
        },
      },
    ],
  },
  plugins: [
    new webpack.DefinePlugin({
      "process.env.NODE_ENV": JSON.stringify(NODE_ENV),
    }),
    new CaseSensitivePathsPlugin(),
    new CircularDependencyPlugin({
      // exclude detection of files based on a RegExp
      exclude: /a\.js|node_modules/,
      // add errors to webpack instead of warnings
      failOnError: true,
    }),
    new DuplicatePackageCheckerPlugin(),
    new HappyPack({
      loaders: ["babel-loader"],
    }),
  ],
};

export default options;