@contrast/route-metrics/lib/esm-hooks/index.mjs

`route-metrics` allows server performance, exclusive of network time, to be compared on a route-by-route basis. It was created to compare server performance with and without `@contrast/agent` being loaded and active.

import Module from 'node:module';
import {MessageChannel} from 'node:worker_threads';

export default async function registerHooks(data, portMessageHandler) {
  if (Module.register) {
    const {port1: mainPort, port2: loaderPort} = new MessageChannel();
    mainPort.on('message', portMessageHandler);
    data = Object.assign({port: loaderPort}, data);
    mainPort.unref();
    await Module.register('./hooks.mjs', {
      parentURL: import.meta.url,
      data,
      transferList: [loaderPort],
    });
  }
}