yaak/plugin-runtime/src/index.worker.ts

import { readFileSync } from 'node:fs';
import path from 'node:path';
import { parentPort, workerData } from 'node:worker_threads';
import { ParentToWorkerEvent } from './PluginHandle';
import { PluginInfo } from './plugins';

new Promise<void>(async (resolve, reject) => {
  const { pluginDir } = workerData;
  const pathMod = path.join(pluginDir, 'build/index.js');
  const pathPkg = path.join(pluginDir, 'package.json');

  let pkg: { [x: string]: any };
  try {
    pkg = JSON.parse(readFileSync(pathPkg, 'utf8'));
  } catch (err) {
    // TODO: Do something better here
    reject(err);
    return;
  }

  const mod = (await import(`file://${pathMod}`)).default ?? {};

  const info: PluginInfo = {
    capabilities: [],
    name: pkg['name'] ?? 'n/a',
    dir: pluginDir,
  };

  if (typeof mod['pluginHookImport'] === 'function') {
    info.capabilities.push('import');
  }

  if (typeof mod['pluginHookExport'] === 'function') {
    info.capabilities.push('export');
  }

  if (typeof mod['pluginHookResponseFilter'] === 'function') {
    info.capabilities.push('filter');
  }

  console.log('Loaded plugin', info.name, info.capabilities, info.dir);

  function reply<T>(originalMsg: ParentToWorkerEvent, payload: T) {
    parentPort!.postMessage({ payload, callbackId: originalMsg.callbackId });
  }

  function replyErr(originalMsg: ParentToWorkerEvent, error: unknown) {
    parentPort!.postMessage({
      error: String(error),
      callbackId: originalMsg.callbackId,
    });
  }

  parentPort!.on('message', async (msg: ParentToWorkerEvent) => {
    try {
      const ctx = { todo: 'implement me' };
      if (msg.name === 'run-import') {
        reply(msg, await mod.pluginHookImport(ctx, msg.payload));
      } else if (msg.name === 'run-filter') {
        reply(msg, await mod.pluginHookResponseFilter(ctx, msg.payload));
      } else if (msg.name === 'run-export') {
        reply(msg, await mod.pluginHookExport(ctx, msg.payload));
      } else if (msg.name === 'info') {
        reply(msg, info);
      } else {
        console.log('Unknown message', msg);
      }
    } catch (err: unknown) {
      replyErr(msg, err);
    }
  });

  resolve();
}).catch((err) => {
  console.log('failed to boot plugin', err);
});