import { Worker, isMainThread, parentPort, workerData } from "node:worker_threads";

function deep(n: number): number {
  return n === 0 ? 0 : deep(n - 1) + 1;
}
function endless(n: number): number {
  return endless(n + 1) + 1;
}

if (isMainThread) {
  for (const mode of ["caught", "uncaught"]) {
    await new Promise<void>((resolve) => {
      // Messages and the error event travel on separate channels, so their
      // relative order is not specified; report both once the worker exits.
      const messages: string[] = [];
      const errors: string[] = [];
      const worker = new Worker(new URL(import.meta.url), { workerData: mode });
      worker.on("message", (text: string) => messages.push(`${mode} message ${text}`));
      worker.on("error", (error: Error) =>
        errors.push(`${mode} error ${error.name} ${error.message} ${error instanceof RangeError}`),
      );
      worker.on("exit", (code: number) => {
        for (const line of [...messages, ...errors]) console.log(line);
        console.log(mode, "exit", code);
        resolve();
      });
    });
  }
  console.log("main", deep(3000));
} else if (workerData === "caught") {
  try {
    endless(0);
  } catch (e) {
    parentPort!.postMessage(`${e instanceof RangeError} ${(e as Error).message}`);
  }
  parentPort!.postMessage(`still running ${deep(3000)}`);
} else {
  parentPort!.postMessage(`before ${deep(2000)}`);
  endless(0);
}