promise-cancellation v1.0.1

promise-cancellation

Nice cancellation for any Promise/A+ implementation

• "Cancelled" promises are forever 'pending'
• Can be used with any Promise/A+

Install

As usual:

yarn add promise-cancellation

or

npm install promise-cancellation

Example

import {Cancellation} from 'promise-cancellation';

function main() {
	const cancellation = new Cancellation();
	
	doSomething(cancellation.token);
	
	if (youChangedYourMind) {
		cancellation.cancel();
	}
}

function doSomething(cancellationToken) {
	return doOneThing()

		// will hang if cancelled, otherwise will act as identity
		.then(cancellationToken)

		.then(doOtherThing);
}

async function doSomethingAsyncAwait(cancellationToken) {
	await doOneThing();

	// as above, this will never resolve if cancelled
	await cancellationToken;

	await doOtherThing();
}

async function doSomethingAgain(cancellationToken) {
	await doOneThing();

	if (cancellationToken.isCancelled()) {
		return;
	}

	await doOtherThing();
}