Registry / web-framework / workerize-loader

workerize-loader

library2.0.2jsnpmunverified

A Webpack loader that moves a module and its dependencies into a Web Worker, automatically reflecting exported functions as asynchronous proxies. Version 2.0.2 is current, supporting Webpack 5. It bundles a tiny RPC implementation, supports synchronous and async worker functions, and works with async/await. Key differentiators: no separate worker file needed, automatically wraps exports as async proxies, and allows instantiable Worker decorators.

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npm install workerize-loader

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INSTALL

IMPORT

SIG · WORKERIZE-LOADER

workerize-loader

web-frameworkjavascriptv2.0.2

Install

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Import

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Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–223 runs

build_error

glibc

node 18–223 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

worker (default import)

✓ import worker from 'workerize-loader!./worker'

✗ const worker = require('workerize-loader!./worker')

CommonJS require may cause issues with webpack loader resolution; always use ESM import syntax.

Worker instance

✓ let instance = worker()

✗ let instance = new worker()

Both work, but the loader returns a function that returns a Worker instance; 'new' is optional.

Inline worker option

✓ import worker from 'workerize-loader?inline!./worker'

Inline option creates a blob URL; useful for CSP restrictions.

Demonstrates basic usage: exports a synchronous function from a worker module, imports via loader, and calls it asynchronously.

// worker.js export function expensive(time) { let start = Date.now(), count = 0; while (Date.now() - start < time) count++; return count; } // index.js import worker from 'workerize-loader!./worker'; let instance = worker(); instance.expensive(1000).then(count => { console.log(`Ran ${count} loops`); });

Debug

Known issues

gotchaUsing CommonJS require instead of import will not trigger webpack loader.

fix

Use ES6 import syntax: import worker from 'workerize-loader!./worker'

affects: >=1.0

gotchaBabel with commonJS transform will break workerize-loader's export detection.

fix

Disable commonJS transform in Babel configuration (e.g., set modules: false).

affects: >=1.0

breakingVersion 2.0.0 dropped support for Webpack 4; only Webpack 5 is supported.

fix

Upgrade to webpack 5 or stay on workerize-loader 1.x.

affects: >=2.0

gotchaWorker files must use ESM export syntax; default exports are not supported.

fix

Use named exports in worker file: export function foo() {}

affects: >=1.0

gotchaIf output.globalObject is set to 'window', HMR may break.

fix

Set output.globalObject to 'this' or remove custom globalObject configuration.

affects: >=1.0.4

Errors

Common errors & fixes

Error: workerize-loader: no exports found in module

Worker module has only default exports or no named exports.

fix

Ensure worker module uses named exports: export function myFunc() {}

Module parse failed: Unexpected token (1:0) You may need an appropriate loader to handle this file type.

Webpack is trying to parse the worker file without workerize-loader applied.

fix

Use correct import syntax: import worker from 'workerize-loader!./worker' or configure loader in webpack.config.

The 'require' function is used in a way in which dependencies cannot be statically extracted

Using dynamic require in worker module.

fix

Use static import statements only in worker module files.

workerize-loader: 'name' option must be a string

Invalid option passed to loader.

fix

Use the correct option format: { loader: 'workerize-loader', options: { name: '[name].[contenthash:8]' } }

Upgrade

Version history

2.0.2latest on npm

Audit

Dependencies

webpackrequiredpeer dependency required for loader functionality

Agent activity

41 hits · last 30 days

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Bingbot

OpenAI (training)

Resources

githubhttps://github.com/developit/workerize-loader ↗

packagehttps://www.npmjs.com/package/workerize-loader ↗