Error hierarchy

All hurried errors extend HurriedError, so you can instanceof HurriedError to detect anything from the library.

HurriedError

Base class. instanceof HurriedError matches every other library error.

TaskError

A handler threw or rejected. The original error is on .cause:

try {
  await thread.run('process', data);
} catch (e) {
  if (e instanceof TaskError) {
    console.error('handler failed:', e.cause);
  }
}

TaskTimeoutError

The call exceeded its timeout. .timeoutMs carries the configured deadline.

try {
  await thread.run(arg, { timeout: 500 });
} catch (e) {
  if (e instanceof TaskTimeoutError) retryWithLongerTimeout();
}

TaskAbortedError

An AbortSignal fired during the call.

const controller = new AbortController();
setTimeout(() => controller.abort(), 100);

try {
  await thread.run(arg, { signal: controller.signal });
} catch (e) {
  if (e instanceof TaskAbortedError) { /* swallow */ }
}

TerminatedError

The worker was deliberately torn down mid-flight via terminate().

const promise = thread.run(arg);
await thread.terminate();        // promise rejects with TerminatedError

WorkerExitedError

The worker exited on its own — process.exit() in task code, an OOM, or a fatal native error — rather than being terminated. Kept distinct from TerminatedError so the *Settled helpers can treat a crashed worker as a recoverable per-item failure instead of a deliberate stop. Exposes the exit code when the runtime reports one.

try {
  await thread.run(arg);
} catch (e) {
  if (e instanceof WorkerExitedError) respawn();
}