Flow control(Multi threading): Web worker + Promise for Inversion of Control

WorkerPromise.js

// Warning!: It is not yet prevented for race condition!
const mine = { js: { type: 'application/javascript' } };

const WorkerPromise = f => {
  let resolve;
  let reject;
  const worker = Object.assign(
    new Worker(
      URL.createObjectURL(
        new Blob([`onmessage = e => postMessage((${f})(e.data));`], mine.js),
      ),
    ),
    { onmessage: e => resolve(e.data), onerror: e => reject(e.data) },
  );
  return data =>
    new Promise((res, rej) => {
      resolve = res;
      reject = rej;
      worker.postMessage(data);
    });
};

export default WorkerPromise;