How to use Immutable.js with redux?

Question

Redux framework is using reducers to change app state in response to an action.

The key requirement is that a reducer cannot modify an existing state object; it must

Answer 1

The accepted answer should not be the accepted answer. You need to initialise state using immutable and then (as mentioned before) use redux-immutablejs

const initialState = Immutable.fromJS({}) // or Immutable.Map({})

const store = _createStore(reducers, initialState, compose(
    applyMiddleware(...middleware),
    window.devToolsExtension ? window.devToolsExtension() : f => f
));

Than use the combineReducers from redux-immutablejs

Extra tip: Using react-router-redux works pretty well so if you would like to add this then replace the reducer from react-router-redux with this:

import Immutable from 'immutable';
import {
    UPDATE_LOCATION
} from 'react-router-redux';

let initialState;

initialState = Immutable.fromJS({
    location: undefined
});

export default (state = initialState, action) => {
    if (action.type === UPDATE_LOCATION) {
        return state.merge({
            location: action.payload
        });
    }

    return state;
};

Just import this into your root reducer

This is also stated in the documentation of redux-immutablejs