redux-saga-fetch_2.js

// sagas.js
function * fetchIncrement () {
  const response = yield call(fetch, "http://haha.com/fetch_1")
  const data = yield call([response, response.json])

  const number = parseInt(data)
  console.log(number)
  return number
}

export function* incrementAsync(){
  const fetchResult = yield call (fetchIncrement); // fetchResult is a Promise object, not 1
  yield put({type: 'INCREMENT_COUNT', payload: fetchResult}) // fetchResult needs to be 1
}

export function* watchIncrementAsync(){
  yield takeEvery('INCREMENT_ASYNC', incrementAsync);
}