Select() function does not work with use-saga-reducer

[evanrolfe]

The problem:
Calling yield select() inside a saga always returns the initial state, and not the actual current state. I need to access the current state inside a saga function, is there a different way to do this or is this a bug that needs fixing?

Steps to reproduce:
In examples/13_saga/src/store.ts, import select from redux-saga/effects:

import {
  call,
  put,
  delay,
  takeLatest,
  takeEvery,
  all,
  select
} from 'redux-saga/effects';

And change delayedDecrementer() to be:

function* delayedDecrementer() {
  const count = yield select(state => state.count);
  console.log(`The count is: ${count}`)
  yield delay(500);
  yield put({ type: 'DECREMENT' });
}

Now, open the app in the browser, click the plus button a few times so the count equals 3 (or any number > 0). Then click "-1 Delayed" button.

What actually happens:
The console logs display the message The count is: 0.

What should happen:
The console logs should show the actual count value before the decrement i.e. The count is: 3.

[dai-shi]

Hi, thanks for reporting.
It looks like a bug in use-saga-reducer.

if I add

    useEffect(() => {                                                      
      stateRef.current = state;
    });

right after const stateRef = useRef(state);,
it seems to work.
(I'm not sure if useEffect runs too late and this case requires useLayoutEffect.)

@azmenak Would you take a look please?

[evanrolfe]

@dai-shi thank you for the quick response!

I can confirm that adding that useEffect() call does seem to fix the problem.

[dai-shi]

Closing this as I filed the issue in the upstream: azmenak/use-saga-reducer#1

[azmenak]

Update: issue has been resolved in use-saga-reducer