webpack.config.js

var path = require("path");

var babelOptions = {
  presets: [
    ["@babel/preset-env", {
        "modules": false,
        "useBuiltIns": "usage",
    }]
  ]
};

module.exports = function (evn, argv) {
 var mode = argv.mode || "development";
 var isProduction = mode === "production";
 console.log("Webpack mode: " + mode);

 return {
  mode: mode,
  devtool: isProduction ? false : "eval-source-map",
  entry: {
    app: ["@babel/polyfill", "./test/Tests.fsproj"]
  },
  output: {
    filename: 'bundle.js',
    path: path.join(__dirname, './public'),
  },
  devServer: {
    contentBase: './public',
    port: 8080
  },
  module: {
    rules: [
      {
        test: /\.fs(x|proj)?$/,
        use: "fable-loader"
      },
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: babelOptions
        },
      }
    ]
  }
 };
}