webpack.config.js

const glob = require("glob");
const path = require("path");
const TerserPlugin = require('terser-webpack-plugin');

const AllFramesAtDocumentStart = glob.sync("./Client/Frontend/UserContent/UserScripts/AllFrames/AtDocumentStart/*.js");
const AllFramesAtDocumentEnd = glob.sync("./Client/Frontend/UserContent/UserScripts/AllFrames/AtDocumentEnd/*.js");
const MainFrameAtDocumentStart = glob.sync("./Client/Frontend/UserContent/UserScripts/MainFrame/AtDocumentStart/*.js");
const MainFrameAtDocumentEnd = glob.sync("./Client/Frontend/UserContent/UserScripts/MainFrame/AtDocumentEnd/*.js");

// Ensure the first script loaded at document start is __firefox__.js
// since it defines the `window.__firefox__` global.
if (path.basename(AllFramesAtDocumentStart[0]) !== "__firefox__.js") {
  throw "ERROR: __firefox__.js is expected to be the first script in AllFramesAtDocumentStart.js";
}

// Ensure the first script loaded at document end is __firefox__.js
// since it also defines the `window.__firefox__` global because PDF
// content does not execute user scripts designated to run at document
// start for some reason. ¯\_(ツ)_/¯
if (path.basename(AllFramesAtDocumentEnd[0]) !== "__firefox__.js") {
  throw "ERROR: __firefox__.js is expected to be the first script in AllFramesAtDocumentEnd.js";
}

module.exports = {
  entry: {
    AllFramesAtDocumentStart: AllFramesAtDocumentStart,
    AllFramesAtDocumentEnd: AllFramesAtDocumentEnd,
    MainFrameAtDocumentStart: MainFrameAtDocumentStart,
    MainFrameAtDocumentEnd: MainFrameAtDocumentEnd
  },
  output: {
    filename: "[name].js",
    path: path.resolve(__dirname, "Client/Assets")
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules\/(?!(readability|page-metadata-parser)\/).*/,
        use: {
          loader: "babel-loader",
          options: {
            presets: [
              ["env", {
                targets: {
                  iOS: "10.3"
                }
              }]
            ]
          }
        }
      }
    ]
  },
  plugins: [
    new TerserPlugin()
  ]
};