rollup.config.js

import replace from "@rollup/plugin-replace";
import fs from "fs";
import path from "path";
import { terser } from "rollup-plugin-terser";

const version = JSON.parse(fs.readFileSync("package.json")).version;
const extras = fs.readdirSync(path.resolve(__dirname, "src/extras"));

const terserOptions = {
  mangle: {
    eval: true,
    module: true,
    safari10: true,
    toplevel: true,
  },
  parse: {},
  compress: {
    unsafe: true,
    arguments: true,
    hoist_funs: true,
    hoist_props: true,
    keep_fargs: false,
    negate_iife: true,
    module: true,
    pure_getters: true,
    passes: 2,
    sequences: 400,
    toplevel: true,
    unsafe_proto: true,
    unsafe_regexp: true,
    unsafe_math: true,
    unsafe_symbols: true,
    unsafe_comps: true,
    unsafe_Function: true,
    unsafe_undefined: true,
  },
  output: {
    comments(node, comment) {
      return /^\* SystemJSProxy [0-9]\./.test(comment.value.trim());
    },
    safari10: true,
  },
  ecma: 5, // specify one of: 5, 2015, 2016, 2017 or 2018
  keep_classnames: false,
  keep_fnames: false,
  ie8: false,
  module: true,
  nameCache: null, // or specify a name cache object
  safari10: true,
  toplevel: true,
  warnings: false,
};

const buildProd = !process.env.dev;

export default [
  mainConfig("system", true),
  buildProd && mainConfig("system", false),
  mainConfig("s", true),
  buildProd && mainConfig("s", false),
  ...extrasConfig(true),
  ...prodExtras(),
].filter(Boolean);

function prodExtras() {
  if (buildProd) {
    return extrasConfig(false);
  } else {
    return [];
  }
}

function mainConfig(name, isMin) {
  const sjs = name === "s";
  let banner;
  if (sjs) {
    banner = !isMin
      ? `/*
* SJS ${version}
* Minimal SystemJSProxy Build
*/`
      : null;
  } else {
    banner = `/*
* SystemJSProxy ${version}
*/`;
  }

  return {
    input: `src/${name}.js`,
    output: {
      file: `dist/${name}${isMin ? ".min" : ""}.js`,
      format: "iife",
      strict: false,
      sourcemap: isMin,
      banner,
    },
    plugins: [
      replace({
        "process.env.SYSTEM_PRODUCTION": sjs ? "true" : "false",
        "process.env.SYSTEM_BROWSER": "true",
      }),
      isMin && terser(terserOptions),
    ],
  };
}

function extrasConfig(isMin) {
  return extras.map((extra) => {
    extra = extra.replace(".js", "");
    return {
      input: `src/extras/${extra}.js`,
      output: {
        file: `dist/extras/${extra}${isMin ? ".min" : ""}.js`,
        format: "iife",
        strict: false,
        compact: true,
        sourcemap: isMin,
      },
      plugins: [
        isMin && terser(terserOptions),
        replace({
          "process.env.SYSTEM_PRODUCTION": isMin ? "true" : "false",
          "process.env.SYSTEM_BROWSER": true,
        }),
      ],
    };
  });
}