Redux saga never runs

Question

I am trying to configure redux-saga v1.1.3 in my application.

I did with the README here my configuration below.

In my project:

npm i redux-saga@1.1.3 --save

I have created rootSaga.js as follow:

import { all } from 'redux-saga/effects'

export default (customSagas) => function* rootSaga() {
  yield all([
    ...customSagas,
  ])
}

I turned the rootSaga.js into a function, because the rootSaga is within the core of my application and I needed to be able to add more customSaga to my application.

This is my updated configureStore.js:

import { routerMiddleware } from 'connected-react-router';
import {
  createStore,
  applyMiddleware,
  compose,
} from 'redux';
import { persistReducer, persistStore } from 'redux-persist';
+ import createSagaMiddleware from 'redux-saga';
import autoMergeLevel2 from 'redux-persist/lib/stateReconciler/autoMergeLevel2';
import { augmentStore } from '@nfen/redux-reducer-injector';

import storage from './storage';
import combineAppReducers from '../reducers';
+ import rootSagas from '../sagas';

function setupCreateReducer(customReducers = {}, reducerConfig) {
  return function createReducer() {
    return combineAppReducers({
      ...customReducers,
    }, reducerConfig);
  };
}

export default function configureStore(customReducers, customSagas, initialState = {}, persistConfig = {}, reducerConfig = {}) {
  const runtimePersistConfig = {
    key: 'root',
    stateReconciler: autoMergeLevel2,
    storage,
    ...persistConfig,
    whitelist: [
      'preferences',
      ...(persistConfig.whitelist || []),
    ],
  };

  let composeEnhancers = compose;
  const reduxSagaMonitorOptions = {};
  /* istanbul ignore next */
  if (__DEV__ && typeof window === 'object') { // eslint-disable-line no-undef
    /* eslint-disable no-underscore-dangle */
    if (window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__) {
      composeEnhancers = window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__({});
    }
    /* eslint-enable */
  }

+  const sagaMiddleware = createSagaMiddleware(reduxSagaMonitorOptions);
-  const middlewares = combineAppMiddlewares([], reducerConfig.history);
+  const middlewares = combineAppMiddlewares([sagaMiddleware], reducerConfig.history);


-  const middlewares = [routerMiddleware(reducerConfig.history)];
+  const middlewares = [sagaMiddleware, routerMiddleware(reducerConfig.history)];

  const enhancers = [applyMiddleware(...middlewares)];

  const createReducer = setupCreateReducer(customReducers, reducerConfig);
  const persistedReducer = persistReducer(runtimePersistConfig, createReducer());
  const store = createStore(
    persistedReducer,
    initialState,
    composeEnhancers(...enhancers),
  );
  // Extensions
+  store.runSaga = sagaMiddleware.run;
+  store.runSaga(rootSagas(customSagas));

  augmentStore(createReducer, store);
  const persistor = persistStore(store);
  return { store, persistor };
}

In there, I use redux and redux-persist, I also configure redux development tools. and have some core features such as preferences being preconfigured and persistent

This is my customSagas.js:

import sessionsSaga from './sessionsSaga';

export default [
  sessionsSaga,
];

This is my sessionSaga.js:

import { takeLatest } from 'redux-saga/effects';

export function* logout() {
  console.log('hello world');
}

export default function* logoutSaga() {
  yield takeLatest('LOGOUT' , logout);
}

And this is how I call the saga in my JSX:

function App() {
    return (
        <Button
          push={() => dispatch({ type: 'LOGOUT' })}
        >
          Logout Saga
        </Button>
    );
}

I can see that the LOGOUT type is dispatched in my redux dev tools, but I can't see the hello world.

Where am I failing?

Answer 1

when you do yield all([...]) in rootSaga you have to call the functions like sessionSaga(). in your code you are just listing the generator functions. see root saga docs

i think something like:

import { all, call } from 'redux-saga/effects'

export default (customSagas) => function* rootSaga() {
  yield all(customSagas.map(saga => call(saga)));
}

could work.