React 사용시 Promise Cancel() 하는 경우

출처 : https://stackoverflow.com/questions/29478751/how-to-cancel-an-emcascript6-vanilla-javascript-promise-chain

While there isn't a standard way of doing this in ES6, there is a library called Bluebird to handle this.

There is also a recommended way described as part of the react documentation. It looks similar to what you have in your 2 and 3rd updates.

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;
    },
  };
};

const cancelablePromise = makeCancelable(
  new Promise(r => component.setState({...}}))
);

cancelablePromise
  .promise
  .then(() => console.log('resolved'))
  .catch((reason) => console.log('isCanceled', reason.isCanceled));

cancelablePromise.cancel(); // Cancel the promise

Taken from: https://facebook.github.io/react/blog/2015/12/16/ismounted-antipattern.html