[Web] to cancel Promise

Reprinted from  to cancel the Promise plug in the wings

const makeCancelable = (promise) => {
  let hasCanceled_ = false;
  const wrappedPromise = new Promise((resolve, reject) => {
    promise.then((val) =>
      hasCanceled_ ? reject({isCanceled: true}) : resolve(val)
    );
    promise.catch((error) =>
      hasCanceled_ ? reject({isCanceled: true}) : reject(error)
    );
  });
  return {
    promise: wrappedPromise,
    cancel() {
      hasCanceled_ = true;
    },
  };
}; 

　　

// Call 
const somePromise = new Promise (r = > setTimeout (r, 1000)); // Create an asynchronous operation 
const cancelable = makeCancelable (somePromise); // add functionality to cancel the asynchronous operation 
cancelable 
  .promise 
  .then ( () => the console.log ( 'resolved')) 
  .catch (({isCanceled, ...} error) => the console.log ( 'isCanceled', isCanceled)); 
// cancel the asynchronous operation 
cancelable.cancel () ;