queue-maplimit

library0.0.3jsnpmunverified

A lightweight concurrency-limited async queue based on Promises, implementing a mapLimit pattern similar to async.mapLimit. Version 0.0.3 provides a simple API to control the maximum number of concurrent async operations. It is dependency-free and designed for node.js and browser environments where Promise-based concurrency control is needed. Compared to alternatives like p-limit or async.queue, it offers a minimal API surface with a single QueueMapLimit class that takes a limit and an add method accepting an array and iteratee.

testing

npm install queue-maplimit

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · QUEUE-MAPLIMIT

queue-maplimit

testingjavascriptv0.0.3

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.

QueueMapLimit

✓ const QueueMapLimit = require('queue-maplimit')

✗ import QueueMapLimit from 'queue-maplimit'

Package uses CommonJS. No ES module version provided.

QueueMapLimit (default import in ESM)

✓ import QueueMapLimit from 'queue-maplimit'

✗ import { QueueMapLimit } from 'queue-maplimit'

In ESM, default import works if using bundler that interops with CJS. Named import fails.

QueueMapLimit (type import in TypeScript)

✓ import QueueMapLimit from 'queue-maplimit'; typeof QueueMapLimit

✗ import { QueueMapLimit } from 'queue-maplimit'

No TypeScript types provided. TypeScript will infer types from JS.

Creates a queue with concurrency limit 2, processes an array with an async iteratee doubling each value, and logs results.

const QueueMapLimit = require('queue-maplimit'); const queue = new QueueMapLimit(2); const arr = [1, 2, 3, 4, 5]; const iteratee = value => new Promise((resolve, reject) => { setTimeout(() => resolve(value * 2), 100); }); queue.add(arr, iteratee).then(result => { console.log('Results:', result); // [2, 4, 6, 8, 10] });

Debug

Known issues

gotchaadd() returns a Promise that resolves with the results array, but if any iteratee rejects, the Promise rejects immediately (no error handling per item).

fix

Handle rejection in .catch() or wrap iteratee to never reject.

affects: <=0.0.3

gotchaThe constructor expects a single number argument (limit). Passing non-number or missing argument throws undefined behavior.

fix

Ensure limit is a positive integer: new QueueMapLimit(5).

affects: <=0.0.3

gotchaarr must be an array; passing other iterables (e.g., Set, generator) will fail silently.

fix

Convert to array first: queue.add([...iterable], iteratee).

affects: <=0.0.3

Errors

Common errors & fixes

TypeError: queue.add is not a function

Importing the package incorrectly, e.g., import { QueueMapLimit } instead of default import in CJS.

fix

Use const QueueMapLimit = require('queue-maplimit') or import QueueMapLimit from 'queue-maplimit'.

UnhandledPromiseRejectionWarning: undefined

QueueMapLimit's add() rejects with undefined when iteratee rejects, leading to unhandled rejection if not caught.

fix

Add .catch() to the add() promise or ensure iteratee never throws.

Cannot read property 'add' of undefined

Forgetting to call new QueueMapLimit(limit) before using queue.add.

fix

Instantiate the queue: const queue = new QueueMapLimit(5);

Upgrade

Version history

0.0.3latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

9 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/Robin-front/queueMapLimit ↗

packagequeue-maplimit ↗

homepagehttps://github.com/Robin-front/queueMapLimit ↗