cancel-token

CancelToken and Cancel Polyfill

This a polyfill of the polyfillable parts of the proposed cancellable promises spec.

See https://github.com/littledan/proposal-cancelable-promises for more details.

$3

``javascript
import {CancelToken} from 'cancel-token';

const source = CancelToken.source();

const result = someCancellableApi(source.token);

eventSource.on('dont-care-about-result-anymore', () {
source.cancel();
});

// This may throw a Cancel if we called source.cancel().
const value = await result;


// Elsewhere, maybe in another library
async function someCancellableApi(cancelToken) {
await doSomeWork(cancelToken);

// I'm outside of a critical section here, so it's ok if I were to throw.
cancelToken.throwIfRequested();

return doSomeMoreWork(cancelToken);
}
``

$3

To test:

npm test

To watch source files and rerun tests when they change:

npm test:watch