workerize-loader-wp5/src/rpc-wrapper.js

Automatically move a module into a Web Worker (Webpack loader)

export default function addMethods(worker, methods) {
  let c = 0;
  let callbacks = {};
  worker.addEventListener("message", e => {
    let d = e.data;
    if (d.type !== "RPC") return;
    if (d.id) {
      let f = callbacks[d.id];
      if (f) {
        delete callbacks[d.id];
        if (d.error) {
          f[1](Object.assign(Error(d.error.message), d.error));
        } else {
          f[0](d.result);
        }
      }
    } else {
      let evt = document.createEvent("Event");
      evt.initEvent(d.method, false, false);
      evt.data = d.params;
      worker.dispatchEvent(evt);
    }
  });
  methods.forEach(method => {
    worker[method] = (...params) =>
      new Promise((a, b) => {
        let id = ++c;
        callbacks[id] = [a, b];
        worker.postMessage({ type: "RPC", id, method, params });
      });
  });
}