Bun Workers

Bun Workers

Bun supports Web Workers and Node.js worker_threads for parallel execution.

Web Workers

Basic Usage

// main.ts
const worker = new Worker(new URL("./worker.ts", import.meta.url));

worker.postMessage({ type: "start", data: [1, 2, 3, 4, 5] });

worker.onmessage = (event) => {
  console.log("Result:", event.data);
};

worker.onerror = (error) => {
  console.error("Worker error:", error.message);
};

// worker.ts
self.onmessage = (event) => {
  const { type, data } = event.data;

  if (type === "start") {
    const result = data.map((x) => x * 2);
    self.postMessage(result);
  }
};

Worker with URL

// Import from file path
const worker = new Worker(new URL("./worker.ts", import.meta.url));

// Or with blob URL
const code = `
  self.onmessage = (e) => {
    self.postMessage(e.data * 2);
  };
`;
const blob = new Blob([code], { type: "application/javascript" });
const worker = new Worker(URL.createObjectURL(blob));

Transferable Objects

// main.ts
const buffer = new ArrayBuffer(1024 * 1024); // 1MB
const view = new Uint8Array(buffer);
view.fill(42);