cancelable-promise

cancelable-promise

A simple Cancelable Promise.

This package is based on ES Promise.

• See caniuse for browser support
• See core-js for polyfills

FYI, you can cancel a fetch request with AbortController & AbortSignal.

• See MDN
• See caniuse

Table of Contents

• Install
• Usage
  • Basic example
  • NodeJS
  • Browser
• API
  • cancelable
  • CancelablePromise
  • CancelablePromise.cancel
  • CancelablePromise.isCanceled
  • Static methods
• Scripts
  • Build
  • Tests
  • End-to-end tests
• Contributing
  • Contributors
• Code of conduct
• License

Install

npm install --save cancelable-promise

Usage

CancelablePromise acts like an ES Promise: you can use Promise.all, Promise.race with your CancelablePromise for example. The only difference is you'll have a cancel method on your promise to cancel future execution of then or catch functions. CancelablePromise will also cancel all callbacks attached to new promises returned by then/catch.

A callback passed to finally will be always executed.

Basic example

import { cancelable, CancelablePromise } from 'cancelable-promise';

const promises = [
  cancelable(new Promise((resolve) => setTimeout(resolve, 1))),
  new CancelablePromise((resolve) => setTimeout(resolve, 1)),
];

for (const promise of promises) {
  promise.then(() => console.log('not logged'));
  promise.cancel();
}
// Nothing will be logged

NodeJS

const { cancelable } = require('cancelable-promise');
cancelable(new Promise((resolve) => resolve('ok')));

Browser

<script src="https://unpkg.com/cancelable-promise@3.0.0/dist/CancelablePromise.min.js"></script>
<script>
  const { cancelable } = window.CancelablePromise;
  cancelable(new Promise((resolve) => resolve('ok')));
</script>

API

cancelable

import { cancelable } from 'cancelable-promise';

/**
 * @param {Promise} arg - a native Promise
 * @returns {CancelablePromise}
 */
cancelable(
  new Promise((resolve) => {
    resolve('ok');
  })
);

CancelablePromise

import CancelablePromise from 'cancelable-promise';

/**
 * @param {(resolve, reject) => void} arg - a promise executor
 * @returns {CancelablePromise}
 */
new CancelablePromise((resolve, reject) => {
  resolve('ok');
});

CancelablePromise.cancel

/**
 * @returns {void}
 */
cancelablePromise.cancel();

CancelablePromise.isCanceled

/**
 * @returns {boolean}
 */
cancelablePromise.isCanceled();

Static methods

Same as Promise static methods.

import CancelablePromise from 'cancelable-promise';

CancelablePromise.resolve();
CancelablePromise.reject();
CancelablePromise.all([promise1, promise2]);
CancelablePromise.race([promise1, promise2]);
CancelablePromise.allSettled([promise1, promise2]);

You can still use the native Promise API and wrap your promise:

import { cancelable } from 'cancelable-promise';

cancelable(Promise.all([promise1, promise2]));
cancelable(Promise.race([promise1, promise2]));
cancelable(Promise.allSettled([promise1, promise2]));

Scripts

Build

Run babel

npm run build

Tests

Run eslint and jest

npm test

End-to-end tests

Run cypress

npm run cypress

Contributing

Feel free to dive in! Open an issue or submit PRs.

Contributors

This project exists thanks to all the people who contribute.

Code of conduct

Contributor Covenant Code of Conduct.

License

MIT License © Alkemics

Changelog

3.1.2 (2020-07-20)

• upgrade dev dependencies