glob-workers

A Node.js library and CLI for processing large numbers of files in parallel using worker threads. Simply specify a glob pattern and worker module to be run on each file that matches the glob.

This is especially useful for CPU-intensive operations on large file collections, such as linting, parsing, transforming code, etc. The library is customizable, letting you configure the number of worker threads, the maximum number of files each worker can process concurrently, and so on.

Usage

npx glob-workers --glob '**/*.txt' --worker './my-worker.mjs'

Where my-worker.mjs contains a default export function that accepts a single WorkerOptions parameter:

// my-worker.mjs
export default function worker(options) {
  // options === { args, filePath, fileContent }
}

WorkerOptions

interface WorkerOptions {
  /** Arguments passed to the worker script. */
  args: string[]
  /** Path of the current file being processed. */
  filePath: string
  /** Content of the current file being processed. */
  fileContent: string
}

CLI Options

--glob, -g (string): The glob pattern of files to process.
--glob-cwd (string): Overrides the default glob `cwd` e.g. process.cwd()
--glob-ignore (string): Ignore pattern for glob matching.

--worker, -w (string): Path to the worker module.
--worker-cwd (string): Overrides the default `cwd` when resolving the worker module e.g. process.cwd()
--worker-max-files (number): Overrides the max number of files concurrently processed by each worker thread.

--max-workers (number): Override the max number of worker threads.
--verbose, -v (boolean): Output debug information.

JavaScript API

npm i glob-workers

import { globWorkers } from 'glob-workers'

await globWorkers({
  glob: '**/*.txt',
  worker: './my-worker.mjs',
})

globWorkers(options: GlobWorkersOptions): Promise<void>

Executes the provided worker module on each file that matches the provided glob pattern.

GlobWorkersOptions

An object with the following properties:

type GlobbyParameters = Parameters<typeof globby>

interface GlobWorkersOptionsCWD {
  /** @default process.cwd() */
  cwd?: URL | string
}

export type GlobWorkersOptions = {
  /** Glob pattern of files to process. */
  glob: GlobbyParameters[0]
  /** Glob options such as cwd, ignore patterns, etc. */
  globOptions?: GlobWorkersOptionsCWD &
    Omit<NonNullable<GlobbyParameters[1]>, 'cwd' | 'absolute'>
  /** Path to the worker module. */
  worker: string
  workerOptions?: GlobWorkersOptionsCWD & {
    /** Arguments passed to the worker module. */
    args?: string[]
    /**
     * Max number of files concurrently processed by each worker thread.
     * @default 50
     */
    maxFiles?: number
  }
  /** Max number of workers threads. */
  maxWorkers?: number
  /** Output debug information. */
  verbose?: boolean
}