np-queue

library2.0.0jsnpmunverified

np-queue (v2.0.0) is a lightweight Promise-based queue library for controlling task concurrency and pausing/resuming execution. It supports TypeScript types and provides an API for adding tasks, wrapping functions to limit concurrency, and queue lifecycle management. Key differentiators: minimal API surface, pause/resume functionality, and optional task keys for deduplication. Release cadence appears irregular (last release unknown). Suitable for Node.js and browser environments.

testing devops

npm install np-queue

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · NP-QUEUE

np-queue

testingjavascriptv2.0.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

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

Queue

✓ import Queue from 'np-queue'

✗ import { Queue } from 'np-queue'

Default export, not named export.

Queue (CommonJS)

✓ const Queue = require('np-queue').default

✗ const Queue = require('np-queue')

CommonJS require requires .default property to access default export.

Queue (TypeScript)

✓ import Queue from 'np-queue'

Same as ESM, types ship with package.

Creates a queue with concurrency 2, adds three tasks, demonstrates pause/resume, and wraps a function.

import Queue from 'np-queue'; const queue = new Queue({ concurrency: 2 }); const task1 = () => new Promise(resolve => setTimeout(() => resolve(1), 1000)); const task2 = () => new Promise(resolve => setTimeout(() => resolve(2), 1000)); const task3 = () => new Promise(resolve => setTimeout(() => resolve(3), 1000)); queue.add(task1).then(console.log); queue.add(task2).then(console.log); queue.add(task3).then(console.log); // Output: 1, 2, and then 3 after 1 second (concurrency 2 means two tasks run simultaneously) queue.pause(); // queue is paused, tasks are deferred queue.resume(); // resumes execution const wrapped = queue.wrap(task1); wrapped().then(console.log);

Debug

Known issues

gotchaUsing 'await' with queue.add() inside an async function causes serial execution instead of concurrent.

fix

Do not await add() if you want concurrent execution; chain via .then() or use Promise.all().

affects: *

gotchaTask keys must not be undefined; providing undefined as key will be ignored.

fix

Provide a defined key (e.g., string or number) to enable deduplication.

affects: *

breakingv2.0.0 changed the default concurrency from Infinity to 1.

fix

If you relied on default Infinity, specify concurrency: Infinity explicitly.

affects: >=2.0.0

gotchaqueue.all() does not guarantee order; results may be in different order than added tasks.

fix

Use queue.add() and track promises manually for ordered results.

affects: *

Errors

Common errors & fixes

import { Queue } from 'np-queue' yields undefined

Queue is a default export, not a named export.

fix

Use import Queue from 'np-queue' instead.

TypeError: require(...) is not a constructor (CommonJS)

Using require without .default gives the module object, not the default export.

fix

Use const Queue = require('np-queue').default;

Tasks are running one by one even though I set concurrency > 1

Using await queue.add() inside an async function serializes the adds.

fix

Do not await; use .then() or add them without await.

Upgrade

Version history

2.0.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

6 hits · last 30 days

node

Resources

githubhttps://github.com/ngtmuzi/np-queue ↗

packagenp-queue ↗

homepagehttps://github.com/ngtmuzi/np-queue#readme ↗