Bundling remote dependencies with rollup

rollup.config.js

const http = require("http");
const https = require("https");

const isRemote = path =>
  path.startsWith("http://") || path.startsWith("https://");

const protocol = url =>
  url.startsWith("https://") ? https : http;

const fetch = url =>
  new Promise((resolve, reject) =>
    protocol(url).get(url, response => {
      let output = "";
      response.on("data", chunk => output += chunk);
      response.on("end", () => resolve(output));
    }).on("error", err => reject(err)));

const resolveURL = {
  name: "URL Resolver",
  resolveId(importee) {
    if (isRemote(importee))
      return importee;
  },
  load(id) {
    if (isRemote(id))
      return fetch(id);
  }
};

export default {
  entry: "plugins/dashboard/public/index.js",
  dest: "plugins/dashboard/public/bundle.js",
  format: "es",
  plugins: [resolveURL]
};