js-aborts

AbortController constructors inspired by Go's context package

✅ Creating AbortControllers that inherit abortion from a parent AbortSignals and can be aborted manually or after a timeout.

✅ Created AbortControllers are Disposable and can be used with using statement.

✅ Supports long timeouts (no wraps around).

✅ Zero dependencies

Disclaimer

For production use I would recommend using AbortSignal.timeout() and AbortSignal.any().

However, there are some issues with leaks if you use them together. My approach focuses on creating derived AbortController rather than AbortSignal to allow manual disposal of not needed controllers to avoid leaks.

Install

npm install js-aborts

API

import { aborts } from 'js-aborts';

🔻aborts.create

function create(...parentSignals: (AbortSignal|undefined)[]): AbortController;

Creates a new AbortController:

• If valid parentSignals are provided, abortion any of them also aborts the returned controller.
• If any of parentSignals is already aborted, the returned controller is also already aborted with the reason of the first aborted parent signal

🔻 aborts.timeout

function timeout(timeoutMs: number, ...parentSignals: (AbortSignal|undefined)[]): AbortController;

Creates a new AbortController that aborts after the specified timeoutMs. If valid parentSignals are provided, abortion any of them also aborts the returned controller. If any of parentSignals is already aborted, the returned controller is also already aborted with the reason of the first aborted parent signal

Usage notes

Example

import { aborts } from 'js-aborts';

async function doSome(arg: string, signal?: AbortSignal) {
    // ...
}

async function doSomeComplex(signal?: AbortSignal) {
    // Create a controller that will be aborted after 5 seconds or when the parent 
    // signal is aborted. Thanks to `using` statement, the created controller will 
    // be disposed (clearing the internal timeout) automatically at the end of the scope.
    using ac = aborts.timeout(5000, signal)
    
    await doSome('first call', ac.signal)
    await doSome('second call', ac.signal)
}

Always dispose the created controllers to avoid resource leaks

Unlike AbortSignal.timeout(), the lib's functions return AbortController rather than AbortSignal.

This is done to allow manual abortion of not needed controllers to avoid leaks of internal timers/listeners.

It's better to dispose the created controllers explicitly when they are not needed anymore:

// In typescript < 5.2:
function myFunc(signal?: AbortSignal) {
    const ac = aborts.timeout(5000, signal)
    try {
        // use ac.signal
    } finally {
        ac.abort()
    }
}

// In typescript >= 5.2:
function myFunc(signal?: AbortSignal) {
    // Unlike standard AbortControllers, the created controller is Disposable
    using ac = aborts.timeout(5000, signal)
    // use ac.signal
}

Warning

Be careful with using statement: it's not currently supported in all environments. The lib is built with ES6 target and polyfills Symbol.dispose that works with the code Typescript generates for using statements, but it's a bit fragile.