WorkTank Esbuild Plugin

Esbuild plugin for WorkTank which enables you to execute whole files in a worker pool, transparently.

Essentially by just importing from a *.worker.js module it will look to you and to TypeScript as if you are just importing async functions, but actually a pool will be created for that module automatically for you, the pool will be proxied, and what you will be actually calling would be those proxied methods.

Install

npm install worktank-esbuild-plugin

Usage

First we need to configure the bundler, mainly we need to tell the "worktank" plugin which files to process:

import esbuild from 'esbuild';
import worktank from 'worktank-esbuild-plugin';

esbuild.build ({
  bundle: true,
  minify: true,
  format: 'esm',
  platform: 'node',
  target: 'es2018',
  entryPoints: ['index.ts'],
  outdir: 'dist',
  plugins: [
    worktank ({
      filter: /\.worker\.(js|ts)$/ // Files matching this regex will be processed
    })
  ]
});

Then we can have a worker file like this:

// example.worker.ts

// You can set any supported WorkTank option like this:
// WORKTANK_OPTIONS = { pool: { name: 'MyExamplePool', size: 5 }, worker: { autoTerminate: 60_000 } }

// Dependencies will be handled automatically
import MyMath from 'some-math-module';

// Some functions to execute in the worker pool
const add = async ( a: number, b: number ) => a + b;
const multiply = async ( a: number, b: number ) => MyMath.multiply ( a * b );

// Exporting all functions
export {add, multiply};

Which we can then use like this:

// index.ts

// Importing functions from the worker file like normal
import {add, multiply} from './example.worker';
// Importing the special injected "pool" export, which is a reference to the `WorkTank` instance that got created automatically for the worker file
import {pool} from './example.worker';

// Calling a function like normal
console.log ( await add ( 5, 10 ) ); // => 15

// Terminating the worker pool, if you want to
pool.terminate ();

Tips

• Setting WORKTANK_OPTIONS in the worker file is entirely optional, but worth thinking about it if you need some customization.
• It's important to annotate the returned function as actually being async or otherwise returning a promise, otherwise the expected types and the actual types will not match.
• This plugin will inject a export called "pool" automatically, which will be a reference to the WorkTank instance created for the worker file.
  • If you want to use it you might want to add this dummy export to your worker file to make types just work: const pool = {} WorkTank<any>; export {pool};.

License

MIT © Fabio Spampinato