Cancellable promise

cancellable_promise.js

export const CancellablePromise = (promise) => {
  let isCancelled = false;

  const wrappedPromise = new Promise((resolve, reject) => {
    promise.then(
      (...args) => (isCancelled ? reject('cancelled') : resolve(...args)),
      error => (isCancelled ? reject('cancelled') : reject(error)),
    );
  });

  return {
    promise: wrappedPromise,
    cancel() {
      isCancelled = true;
    },
  };
};

const fetch_dogs_promise = CancellablePromise( fetchTheDogs() );
fetch_dogs_promise.cancel();