rollup-plugin-worker

3.0.4 verified Mon Apr 27 auth: no javascript

Rollup plugin to bundle Web Workers using a custom prefix import syntax (e.g., `worker!./worker.js`). v3.0.4 supports Rollup 3.x. It allows specifying worker-specific plugins and enables uglification. Provides TypeScript types. Differentiator: uses a prefix syntax rather than URL or inline blob, enabling easy bundling.

Common errors

error Error: Cannot find module 'rollup-plugin-worker' ↓

cause Package not installed or incorrect import path.

fix

npm install rollup-plugin-worker --save-dev

error TypeError: worker is not a function ↓

cause Using default import incorrectly (e.g., import { worker } instead of import worker).

fix

Use default import: import worker from 'rollup-plugin-worker'

error Error: Could not resolve 'worker!./worker.js' ↓

cause Plugin not properly configured or prefix mismatch.

fix

Check that rollup-plugin-worker is in plugins array and prefix matches import path (e.g., 'worker!').

Warnings

breaking Plugin requires Rollup ^3.0.0; does not work with Rollup 2.x. ↓

fix Upgrade to Rollup 3.x or use rollup-plugin-worker@2.x for Rollup 2 compatibility.

gotcha The prefix 'worker!' is required by default; if changed, ensure import statements match. ↓

fix Use the same prefix in both plugin options and import paths.

gotcha Plugins passed in the `plugins` option are used only for worker bundle; do not include the main bundle plugins unintentionally. ↓

fix Define separate plugins array for worker processing if needed.

deprecated uglify option is boolean; consider using terser or other minifier plugins instead. ↓

fix Set uglify: false and use @rollup/plugin-terser for minification.

Install

npm install rollup-plugin-worker

yarn add rollup-plugin-worker

pnpm add rollup-plugin-worker

Imports

default

wrong

const worker = require('rollup-plugin-worker');

correct

import worker from 'rollup-plugin-worker'

ESM-only since v3; CommonJS require() works in Node.

Worker

wrong

import { Worker } from 'worker!./workers/worker.js'

correct

import Worker from 'worker!./workers/worker.js'

Default import from the prefix path, not a named export.

WebWorker (TypeScript declaration)

wrong

declare module 'worker!*' { export class WebWorker extends Worker { constructor(); } }

correct

declare module 'worker!*' { class WebWorker extends Worker { constructor(); } export default WebWorker; }

The default export is named WebWorker in the declaration.

Quickstart

Configures rollup-plugin-worker in rollup.config.js and shows usage in main.js with a custom worker import prefix.

// rollup.config.js
import worker from 'rollup-plugin-worker';

export default {
  input: 'src/main.js',
  plugins: [
    worker({
      prefix: 'worker!',
      plugins: [],
      uglify: false,
    }),
  ],
  output: {
    file: 'dist/bundle.js',
    format: 'iife',
  },
};

// src/main.js
import MyWorker from 'worker!./worker.js';
const w = new MyWorker();
w.postMessage('hello');