Race condition in 0.10.x

I’ve just upgraded to 0.10.4 and also tried this in 0.10.0.

I’m now finding that take has become a little deaf during page load.

I have the following Saga that work fine in 0.9.5, that I’ve added some logging to.

export function* loadSearchResultsSaga(action) {
  console.log('Put SEARCH_RESULTS_REQUESTED');

  yield put(searchResultsActions.loadSearchResults(action));

  console.log('Take SEARCH_RESULTS_SUCCESS');

  yield take([
    searchResultsTypes.SEARCH_RESULTS_SUCCESS,
    searchResultsTypes.SEARCH_RESULTS_FAILURE,
  ]);

  console.log('Put LOADING FINNISH');

  yield put(appStateActions.loadingFinish());
}

However in 0.10.x it gets stuck at the take.

To dig into this a bit further I’ve added the following Saga to log out all the redux actions.

function* log() {
    yield* takeEvery('*', function* (action) {
      console.log('Action:', action.type);
    });
  }

This leads to the following output in the console.

searchResultsSagas.js:118 Action: SET_SEARCH_RESULTS_TRACKING_FLAG
searchResultsSagas.js:28  Put SEARCH_RESULTS_REQUESTED
searchResultsSagas.js:118 Action: SEARCH_RESULTS_REQUEST
searchResultsSagas.js:118 Action: LOCATION_UPDATED
searchResultsSagas.js:118 Action: HASH_UPDATED
client.js:55              [HMR] connected
searchResultsSagas.js:118 Action: SEARCH_RESULTS_SUCCESS
searchResultsSagas.js:35  Take SEARCH_RESULTS_SUCCESS

So it would seem that the Redux action is firing before the take has an opportunity to run. I’m guessing this is caused by a delay in the response to yield put on the previous line.

[yelouafi]

https://github.com/yelouafi/redux-saga/releases/tag/v0.10.5

[SpainTrain]

nit: this would have perhaps been better behind a minor version bump given that this breaks code that relies on the 0.10.0-0.10.4 behavior