createConcurrentRequest.js

const createConcurrentRequest = () => {
  let lastReq;
  return async (request, ...params) => {
    let myReq = (lastReq = request(...params));
    let response = null;
    let error = null;

    do {
      try {
        error = null;
        response = await (myReq = lastReq);
      } catch (e) {
        error = e;
      }
    } while (myReq !== lastReq);

    if (error) throw error;
    return response;
  };
};

// api.example.js

export class ManualError extends Error {}

const concurrentFetchData = createConcurrentRequest();

export const fetchData = payload => concurrentFetchData(fetch, payload);
export const fetchDataCancel = () => concurrentFetchData(() => { throw new ManualError() });

// workflow.example.js

handleFetch = async payload => {
  try {
    this.onUpdate(await fetchData(payload))
  } catch (error) {
    if (error instanceof ManualError) this.reset()
    else this.onError(error)
  }
}

handleCancel = () => fetchDataCancel()