store.getstate() evaluate to undefined - react-native

Question

in a react-native project,I keep hitting in this error:
state is undefined, evaluating store.getstate()
//store.js
const composeEnhancers =
typeof window === "object" && window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__
? window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__({})
: compose;
const enhancer = composeEnhancers(applyMiddleware(thunk));
const Store = createStore(
combineReducers(
{
form: formReducer,
appointmentsReducer
},
enhancer
)
);
console.log(Store.getState());
export default Store;`
//reducer.js
import {
FETCH_APPOINTMENTS_BEGIN,
FETCH_APPOINTMENTS_SUCCESS,
FETCH_APPOINTMENTS_FAILURE
} from '../actions/appointmentsAction';
const initialState = {
data: [],
loading: false,
error: null
};
export default function appointmentsReducer(state = initialState, action) {
switch(action.type) {
case FETCH_APPOINTMENTS_BEGIN:
return {
...state,
loading: true,
error: null
};
case FETCH_APPOINTMENTS_SUCCESS:
return {
...state,
loading: false,
data: action.payload.appointments
};
case FETCH_APPOINTMENTS_FAILURE:
return {
...state,
loading: false,
error: action.payload.error,
data: []
};
default:
return state;
}
}
//actions.js
import { listUrl } from "../cst";
export const FETCH_APPOINTMENTS_BEGIN = "FETCH_APPOINTMENTS_BEGIN";
export const FETCH_APPOINTMENTS_SUCCESS = "FETCH_APPOINTMENTS_SUCCESS";
export const FETCH_APPOINTMENTS_FAILURE = "FETCH_PRODUCTS_FAILURE";
export const fetchAppointmentsBegin = () => ({
type: FETCH_APPOINTMENTS_BEGIN
});
export const fetchAppointmentsSuccess = appointments => ({
type: FETCH_APPOINTMENTS_SUCCESS,
payload: { appointments }
});
export const fetchAppointmentsFailure = error => ({
type: FETCH_APPOINTMENTS_FAILURE,
payload: { error }
});
export function fetchAppointments() {
return dispatch => {
dispatch(fetchAppointmentsBegin());
return fetch(listUrl)
.then(handleErrors)
.then(res => res.json())
.then(json => {
dispatch(fetchApointmentsSuccess(json.appointment));
return json.appointment;
})
.catch(error => dispatch(fetchAppointmentsFailure(error)));
};
}
// Handle HTTP errors since fetch won't.
function handleErrors(response) {
if (!response.ok) {
throw Error(response.statusText);
}
return response;
}
// app.js
export default function App() {
return (
<Provider store={Store}>
<Navigation />
</Provider>
);
}
//list rendrer component :
const mapStateToProps = state => ({
data: state.appointments.data,
loading: state.loading,
error: state.error
});
the console.log of store.getstate() gives :
Object {
"appointmentsReducer": Object {
"data": Array [],
"error": null,
"loading": false,
},
"form": Object {},
I'm not sure where the problem is.
Is it due to the asynchronous call not being handled properly?
If I use saga to handle the fetch, will it resolve the problem?
Any help would be appreciated .