worker

Portable module workers with the Web Worker messaging contract.

Browsers and Deno use the native worker. Bun adds a compatibility preload, while Node adapts worker_threads and bootstraps Web Worker globals. Worker scripts should use self, events, and postMessage rather than runtime-specific messaging APIs.

import Worker from "@rcompat/worker";
import type {
  Worker as WorkerContract, WorkerConstructor, WorkerOptions,
} from "@rcompat/worker";

Worker constructor#

Runtime-selected portable worker constructor.

new Worker(
  input: string | URL,
  options?: WorkerOptions,
): WorkerContract;

Example

const worker = new Worker(new URL("./worker.js", import.meta.url), {
  name: "example",
});
worker.postMessage("hello");

Types#

Worker#

Portable worker instance and messaging contract.

Worker extends EventTarget, including its standard listener and dispatch methods.

Worker members#

Worker.onerror#

Callback invoked for worker execution errors.

onerror: ErrorHandler;

Worker.onmessage#

Callback invoked for messages from the worker.

onmessage: MessageHandler;

Worker.onmessageerror#

Callback invoked when an incoming message cannot be deserialized.

onmessageerror: MessageHandler;

Worker.postMessage#

Sends a structured-cloneable value and optional transferables.

postMessage(message: unknown, transfer?: Transferable[]): void;

Worker.terminate#

Stops worker execution.

terminate(): void;

WorkerConstructor#

Runtime-selected portable worker constructor.

Example

const worker = new Worker(new URL("./worker.js", import.meta.url), {
  name: "example",
});
worker.postMessage("hello");

type WorkerConstructor = new (
  input: string | URL,
  options?: WorkerOptions,
) => Worker;

WorkerOptions#

Shared options for constructing a portable module worker.

type WorkerOptions = {
  // Runtime-visible worker name.
  name?: string;
  // Worker execution mode.
  // Default: `"module"`
  type?: "module";
};

Supporting contracts#

These handler aliases support the public worker properties.

ErrorHandler#

Error-event callback assigned to a worker.

type ErrorHandler = ((event: ErrorEvent) => unknown) | null;

MessageHandler#

Message-event callback assigned to a worker.

type MessageHandler = ((event: MessageEvent) => unknown) | null;