procession

library3.0.2jsnpmunverified

Procession is an asynchronous message queue library for JavaScript and TypeScript. The current stable version is 3.0.2, released in July 2022. It provides backpressure-aware queues for coordinating concurrent tasks, with a simple API for push and pull operations. Key differentiators include its lightweight footprint, no external runtime dependencies, and support for both Node.js and browser environments. It uses a Promise-based interface and supports multiple queue strategies like FIFO and prioritized queues.

messaging

npm install procession

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · PROCESSION

procession

messagingjavascriptv3.0.2

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 'procession'

✗ import Queue from 'procession'

Queue is a named export, not a default export.

push

✓ import { push } from 'procession'

push is a named export used to enqueue items.

pull

✓ import { pull } from 'procession'

✗ const { pull } = require('procession')

Since v3, ESM is required; CommonJS require will fail.

Creates a queue, enqueues two items using push, then dequeues them using pull, demonstrating basic operations.

import { Queue, push, pull } from 'procession'; async function main() { const queue = new Queue(); await push(queue, 'task1'); await push(queue, 'task2'); const result1 = await pull(queue); console.log(result1); // 'task1' const result2 = await pull(queue); console.log(result2); // 'task2' } main().catch(console.error);

Debug

Known issues

breakingIn v3, the package is ESM-only; using require() will throw a Module not found error.

fix

Use import syntax, or downgrade to v2 if CommonJS is required.

affects: >=3.0.0

gotchapush and pull are async functions and must be awaited; forgetting await can lead to unresolved promises.

fix

Always use await when calling push or pull.

affects: >=1.0.0

deprecatedThe 'size' property on Queue instances is deprecated in v3; use the 'length' property instead.

fix

Use queue.length instead of queue.size.

affects: >=3.0.0

gotchaQueue does not support infinite capacity; it has a default maximum of 1024 items. Pushing beyond capacity will reject the promise.

fix

Check queue.length before pushing, or configure a larger capacity via constructor options.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: queue.push is not a function

Using push as a method on the Queue instance, but push is a standalone function.

fix

Use import { push } from 'procession' and call push(queue, item).

Module not found: Error: Can't resolve 'procession'

Package not installed or ESM-only import with require() in v3.

fix

Run npm install procession, and use import syntax instead of require().

UnhandledPromiseRejectionWarning: Error: Backpressure limit exceeded

Queue capacity exceeded; default max 1024 items.

fix

Increase capacity via new Queue({ max: 2048 }) or drain the queue before adding more.

Upgrade

Version history

3.0.2latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

14 hits · last 30 days

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Resources

githubhttps://github.com/bigeasy/procession ↗

packageprocession ↗

homepagehttps://github.com/bigeasy/procession ↗