TaskQueue

A minimalist async task queue/serializer for JavaScript.

Overview

TaskQueue ensures async operations execute in FIFO (first-in, first-out) order, preventing race conditions when multiple async tasks need to be serialized.

Installation

Use directly as an ES module via jsdelivr:

import { TaskQueue } from 'https://cdn.jsdelivr.net/gh/mesgjs/task-queue/src/task-queue.esm.js';

Usage

import { TaskQueue } from 'https://cdn.jsdelivr.net/gh/mesgjs/task-queue/src/task-queue.esm.js';

const queue = new TaskQueue();

// Queue async tasks
const result1 = await queue.add(async () => {
  // Your async operation
  return 'result';
});

const result2 = await queue.add(async () => {
  // This runs after result1 completes
  return 'another result';
});

API

new TaskQueue()

Creates a new task queue instance.

add(callback) (alias task)

Queues an async function for execution.

• Parameters: callback - Async function to execute
• Returns: Promise that resolves with the callback's return value
• Throws: Rejects if the queue is shutting down

cancel(callback, { resolve, reject })

Cancels a queued task. By default, promises reject with Cancelled.

• Parameters:
  • callback - The callback function to cancel
  • resolve - The promise will resolve to this if not undefined
  • reject - The promise will reject with this if not undefined
• Returns: true if cancelled, false if not found

shutdown()

Shuts down the queue and rejects all pending operations with Shutting down.

size

Returns the number of pending operations in the queue.

License

See LICENSE file for details.

Copyright

Copyright 2025-2026 Kappa Computer Solutions, LLC and Brian Katzung