threadedClass

1.4.0 verified Fri May 01 auth: no javascript

Fork a class instance into a separate thread (Node.js Worker Threads or Web Workers) while preserving TypeScript typings. v1.4.0 is stable with a mature API. Key differentiators: one-liner thread instantiation, automatic method promisification, optional auto-restart on crash, and thread pooling via ThreadedClassManager. Actively maintained with frequent releases, supports Node ≥8 and modern browsers.

Common errors

error TypeError: threadedClass is not a function ↓

cause Default import used instead of named import.

fix

Use import { threadedClass } from 'threadedclass' or const { threadedClass } = require('threadedclass').

error Cannot find module './professor.js' ↓

cause The compiled JS file path is incorrect or the module is not yet compiled.

fix

Ensure the path points to the .js file after compilation (e.g., ./professor.js). Compile TypeScript first.

error Error: Class constructor must be invoked with 'new' ↓

cause Passing the class object directly instead of the export name string in Node.js.

fix

Use the second argument as a string: threadedClass('./professor.js', 'Professor', ...). In browser, you must pass the class reference.

Warnings

gotcha The module path must point to the compiled JavaScript file, not the TypeScript source. Using .ts will cause runtime errors. ↓

fix Use the compiled output path (e.g., './professor.js').

deprecated The `threadUsage` option is deprecated. Use `ThreadedClassManager.setThreadUsage()` for thread pool control. ↓

fix Use `ThreadedClassManager.setThreadUsage(0.1)` instead of passing `threadUsage` in config.

breaking In v1.0.0, the `threadedClass` function returned the instance directly (sync). Since v1.1.0 it returns a Promise, breaking old code that did not use await. ↓

fix Add `await` before calling `threadedClass()`.

gotcha Properties of the class are not accessible on the forked instance: only methods are promisified. Accessing a property returns `undefined`. ↓

fix Convert properties to getter methods (e.g., `getName()` instead of `name`).

gotcha In browser environments, you must provide `pathToWorker` in the config, otherwise the worker script won't be found. ↓

fix Set config option `pathToWorker: 'lib/threadedclass-worker.js'`.

Install

npm install threadedclass

yarn add threadedclass

pnpm add threadedclass

Imports

threadedClass

wrong

import threadedClass from 'threadedclass'

correct

import { threadedClass } from 'threadedclass'

Default export does not exist; always use named import.

ThreadedClassManager

wrong

const ThreadedClassManager = require('threadedclass').ThreadedClassManager

correct

import { ThreadedClassManager } from 'threadedclass'

Named import in ESM. In CJS, use const { ThreadedClassManager } = require('threadedclass').

ThreadedClassConfig
```
import type { ThreadedClassConfig } from 'threadedclass'
```
TypeScript consumers can import the config type for type safety. Not available at runtime.

Quickstart

Creates a forked instance of Professor class running in a separate thread. Constructor arguments are passed as array; all methods become async.

import { threadedClass } from 'threadedclass';

// Assume ./professor.ts exports class Professor with methods like talkAboutAncientGreece()
const mrSmith = await threadedClass<Professor>(
  './professor.js', // path to compiled JS file
  'Professor',
  ['maths', 'greek'], // constructor args
  { autoRestart: true } // optional config
);

// All methods return promises
const story = await mrSmith.talkAboutAncientGreece();
console.log(story);