p-finally

What is p-finally?

The p-finally npm package is designed to allow you to attach a handler that will be called when a promise is settled (either fulfilled or rejected). This is useful for running cleanup code or finalizing operations, regardless of the promise's outcome.

What are p-finally's main functionalities?

Attaching a finally handler to a promise

This feature allows you to execute code after a promise has been settled, regardless of whether it was fulfilled or rejected. It's particularly useful for cleanup operations.

const pFinally = require('p-finally');

const promise = new Promise((resolve, reject) => {
  // Some asynchronous operation
});

pFinally(promise, () => {
  // Code to run on promise settlement
});

Other packages similar to p-finally

bluebird

Bluebird is a comprehensive promise library that includes a .finally() method among its wide array of features. Compared to p-finally, Bluebird offers a much broader set of promise-related utilities, but it's also larger in size, which might be an overkill for projects only needing a finally functionality.

q

Q is another promise library that supports a .finally() method. Similar to Bluebird, Q provides a wide range of promise manipulation capabilities. It's more feature-rich than p-finally but also larger, making p-finally a lightweight alternative if the finally functionality is the main requirement.

README

p-finally

Promise#finally() ponyfill - Invoked when the promise is settled regardless of outcome

Useful for cleanup.

Install

$ npm install p-finally

Usage

import pFinally from 'p-finally';

const directory = createTempDirectory();

await pFinally(write(directory), () => {
	cleanup(directory);
});

API

pFinally(promise, onFinally?)

Returns a Promise.

onFinally

Type: Function

Note: Throwing or returning a rejected promise will reject promise with the rejection reason.

Related

• p-try - Promise.try() ponyfill - Starts a promise chain
• More…

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