React Testing Library with Redux - Mocking Axios in action creator - javascript

I have an app I'm adding integration tests to for learning React Testing Library.
It's built in MERN stack, along with Redux for state management.
My test wrapper is a standard setup:
import React from 'react';
import { render as rtlRender } from '#testing-library/react';
import { createStore, applyMiddleware, compose } from 'redux';
import { Provider } from 'react-redux';
import thunk from 'redux-thunk';
import rootReducer from '../reducers';
const render = (
ui,
{
initialState,
store = createStore(rootReducer, compose(applyMiddleware(thunk))),
...renderOptions
} = {}
) => {
const Wrapper = ({ children }) => {
return <Provider store={store}>{children}</Provider>;
};
return rtlRender(ui, { wrapper: Wrapper, ...renderOptions });
};
export * from '#testing-library/react';
export { render };
At the moment I'm trying to test a login form and errors that are returned when fields aren't valid.
import React from 'react';
import { Router } from 'react-router';
import '#testing-library/jest-dom';
import { createMemoryHistory } from 'history';
import { render, screen, fireEvent, waitFor } from '../../../utils/test-utils';
import Login from '../login';
jest.mock('axios', () => {
return {
post: jest.fn()
};
});
describe('<Login/>', () => {
beforeEach(() => {
// Some requirements for the component to render in the test
const history = createMemoryHistory();
const state = '';
history.push('/', state);
render(
<Router history={history}>
<Login history={history} />
</Router>
);
});
test('should show empty email error', async () => {
fireEvent.input(screen.getByRole('textbox', { name: /email/i }), {
target: {
value: ''
}
});
fireEvent.submit(screen.getByRole('button', { name: /login/i }));
await waitFor(() => {
expect(screen.getByText(/email field is required/i)).toBeInTheDocument();
});
});
});
Unfortunately, when I run this test it gives me TypeError: Cannot read property 'then' of undefined and I can't figure out why
My action looks like:
export const loginUser = (userData) => (dispatch) => {
return axios
.post('/api/users/login', userData)
.then((res) => {
const { token } = res.data;
localStorage.setItem('jwtToken', token);
setAuthToken(token);
const decoded = jwt_decode(token);
dispatch(setCurrentUser(decoded));
})
.catch((err) =>
dispatch({
type: GET_ERRORS,
payload: err.response.data
})
);
};
Instead of testing the actions/reducers in my codebase I'd rather test what the user should see, which is what I've read Testing Library encourages.
I'm also using redux hooks - useDispatch/useSelector, throughout my app.
Any help would be grateful :)

Related

React-Native (redux) error: Could not find "store" in context of "Connect(App)"

I'm getting this weird error in my react-native app. Where I'm using redux to save the user when its is fetched from the firebase database.
Here is the error:
and here is my code in App.js:
import { StatusBar } from 'expo-status-bar';
import React, { useEffect } from 'react';
import { StyleSheet, Text, View, ToastAndroid } from 'react-native';
import firestore from '#react-native-firebase/firestore';
import RNBootSplash from "react-native-bootsplash";
import auth from '#react-native-firebase/auth';
// Navigation
import { NavigationContainer } from '#react-navigation/native';
import BottomTabNavigator from './src/navigation/BottomTabNavigation';
import AuthenticationStack from './src/navigation/AuthenticationStack';
// redux imports
import { Provider } from 'react-redux';
import { saveUserPrefs, saveUser } from './src/redux';
import {store} from './src/redux'
import { connect } from 'react-redux';
const App = (props) => {
const { saveUserPrefs, saveUser } = props;
let isLoggedIn = false;
useEffect(() => {
auth().onAuthStateChanged((user) => {
// if not already login go back to login screen
if(!user){
isLoggedIn = false;
} else {
isLoggedIn = true
RNBootSplash.hide({ fade: true }); // hide the splash screen
ToastAndroid.show("Logged In", ToastAndroid.SHORT);
// save the user & userPrefs in store (redux)
saveUser(user);
saveUserPrefs(user.uid);
}
});
}, [])
return (
<Provider store={store}>
<NavigationContainer>
{isLoggedIn ? <BottomTabNavigator /> : <AuthenticationStack />}
</NavigationContainer>
</Provider>
);
}
const mapStateToProps = (state) => ({
userReducer: state.userReducer
})
export default connect(mapStateToProps, { saveUserPrefs , saveUser})(App);
and here is my redux code:
import axios from 'axios';
import thunk from 'redux-thunk';
import { combineReducers, createStore, applyMiddleware } from 'redux'
import firestore from '#react-native-firebase/firestore';
// Actions
export const saveUserPrefs = (userId) => {
return async (dispatch) => {
try {
console.log('in userlogin function');
const data = await firestore().collection('Users').doc(userId).collection('userPrefs').get();
dispatch({ type: 'SAVE_USER_PREFS', payload: data.docs[0]._data });
} catch (err) {
dispatch({ type: 'ON_ERROR', payload: err });
}
}
}
export const saveUser = (user) => {
return async (dispatch) => {
try {
dispatch({ type: 'SAVE_USER', payload: user})
} catch (err) {
dispatch({ type: 'ON_ERROR', payload: err });
}
}
}
// reducers
const userReducer = (state = {}, action) => {
switch(action.type){
case 'SAVE_USER_PREFS':
return {
...state,
userPrefs: action.payload
}
case 'SAVE_USER':
return {
...state,
user: action.payload
}
case 'ON_ERROR':
return {
...state,
appError: action.payload
}
default:
return state;
}
}
// root reducer
export const rootReducer = combineReducers({
userReducer,
})
// store
export const store = createStore(rootReducer, applyMiddleware(thunk));
I'm new to redux but I read that I have to put the connect method in the component I'm using to get the actions in order to save in the store.
in the App component you cannot connect to the reduxjust wrap your App within another component, that have the Provider
Example code
const AppWrapper = () => {
return (
<Provider store={store}>
<App />
</Provider>
);
};
And remember to delete <Provider store={store}> in your App component

Function not receiving updated redux state even on re-render

I'm currently using Redux, Redux Thunk with NextJS and been trying to figure out how to access the updated redux state inside a function of a functional component.
As you can see in my code below, in the handleSubmit function, I want to update the redux state and then check the state value and decided which route it should take the user to.
Previously in my old project, using mapStateToProps with a Class component, I was able to access the updated redux state inside my handleSubmit function however when using a functional component both options (useSelector hook or mapStateToProps with connect()) doesn't seem to work.
At first I thought the component wasn't re-rendering however when checking the state in useEffect(), I can see that the state is getting updated and the component is able to view the updated values.
Is there something I'm clearly missing or is this way not possible with functional components?
loginPage.tsx
import LoginForm, { FormData } from 'components/Forms/LoginForm';
import Layout from 'components/Layout';
import { FORM_ERROR } from 'final-form';
import StatusCodes from 'lib/enums/statusCodes';
import { storeAuthToken } from 'lib/helpers/auth';
import { useRouter } from 'next/router';
import React, { useEffect } from 'react';
import { useDispatch, useSelector } from 'react-redux';
import { ApplicationState } from 'redux/store';
const LoginPage = () => {
const router = useRouter();
const dispatch = useDispatch();
const { auth } = useSelector((state: ApplicationState) => ({ auth: state.auth }));
const handleSubmit = async (values: FormData) => {
if (values && values.username && values.password) {
try {
// Updates redux store
await storeAuthToken(dispatch, values.username, values.password);
} catch (error) {
if (error === StatusCodes.BadRequest) {
return { [FORM_ERROR]: 'Sorry, you have entered incorrect details. Please try again' };
} else {
return { [FORM_ERROR]: 'Sorry, there was an issue trying to log you in' };
}
}
// Can't see updated values
console.log('Auth: ', auth);
if (auth.parsedJwt && auth.parsedJwt.changePassword) {
router.push({ pathname: '/update-password' });
return;
}
router.push('/dashboard');
}
};
useEffect(() => {
// Can see the updated values
console.log('New Auth: ', auth);
}, [auth]);
return (
<Layout hideProfileMenu title="Login">
<LoginForm onSubmit={handleSubmit} />
</Layout>
);
};
export default LoginPage;
I've attached the store and reducer incase I've set it up wrong.
store.tsx
import Auth from 'lib/interfaces/auth';
import { Context, createWrapper, HYDRATE, MakeStore } from 'next-redux-wrapper';
import { AnyAction, applyMiddleware, CombinedState, combineReducers, createStore, Dispatch, Reducer } from 'redux';
import thunkMiddleware, { ThunkAction, ThunkDispatch, ThunkMiddleware } from 'redux-thunk';
import authReducer from './auth/reducer';
export interface ApplicationState {
auth: Auth
}
const isDebug = process.env.NODE_ENV !== 'production';
const bindMiddleware = (middleware: ThunkMiddleware) => {
if (isDebug) {
const { composeWithDevTools } = require('redux-devtools-extension');
return composeWithDevTools(applyMiddleware(middleware));
}
return applyMiddleware(middleware);
};
const combinedReducer: Reducer<ApplicationState> = combineReducers<ApplicationState>({
auth: authReducer
});
const reducer = (state: ApplicationState, action: AnyAction) => {
if (action.type === HYDRATE) {
const nextState: CombinedState<ApplicationState> = {
...state,
...action.payload
};
return nextState;
} else {
return combinedReducer(state, action);
}
};
const makeStore: MakeStore<ApplicationState> = (_context: Context) => createStore(reducer as Reducer<ApplicationState, AnyAction>, bindMiddleware(thunkMiddleware));
export const wrapper = createWrapper<ApplicationState>(makeStore, { debug: isDebug });
reducer.tsx
import Auth from 'lib/interfaces/auth';
import { Reducer } from 'redux';
import { ActionTypes, AuthAction } from './actions';
const reducer: Reducer<Auth, AuthAction> = (state: Auth = {} as Auth, action: AuthAction): Auth => {
switch (action.type) {
case ActionTypes.UpdateToken:
return Object.assign({}, state, { token: action.token });
case ActionTypes.UpdateRefreshToken:
return Object.assign({}, state, { refreshToken: action.refreshToken });
case ActionTypes.UpdateParsedJwt:
return Object.assign({}, state, { parsedJwt: action.parsedJwt });
case ActionTypes.UpdateUuid:
return Object.assign({}, state, { uuid: action.uuid });
default:
return state;
}
};
export default reducer;
I think the simplest solution is to return the auth object from 'storeAuthToken' as it keeps the error handling and result in the same logical flow, and it fixes the asynchronous issue identified in the comments.
import LoginForm, { FormData } from 'components/Forms/LoginForm';
import Layout from 'components/Layout';
import { FORM_ERROR } from 'final-form';
import StatusCodes from 'lib/enums/statusCodes';
import { storeAuthToken } from 'lib/helpers/auth';
import { useRouter } from 'next/router';
import React, { useEffect } from 'react';
import { useDispatch } from 'react-redux';
import { ApplicationState } from 'redux/store';
const LoginPage = () => {
const router = useRouter();
const dispatch = useDispatch();
const handleSubmit = async (values: FormData) => {
if (values && values.username && values.password) {
try {
// Updates redux store
const authResult = await storeAuthToken(dispatch, values.username, values.password);
if (authResult.parsedJwt && authResult.parsedJwt.changePassword) {
router.push({ pathname: '/update-password' });
return;
}
} catch (error) {
if (error === StatusCodes.BadRequest) {
return { [FORM_ERROR]: 'Sorry, you have entered incorrect details. Please try again' };
} else {
return { [FORM_ERROR]: 'Sorry, there was an issue trying to log you in' };
}
}
router.push('/dashboard');
}
};
return (
<Layout hideProfileMenu title="Login">
<LoginForm onSubmit={handleSubmit} />
</Layout>
);
};
export default LoginPage;

Test React Component using Redux and react-testing-library

I am new to testing redux connected components in React and trying to figure out how to test them.
Currently I'm using react-testing-library and having trouble setting up the my renderWithRedux function to correctly setup redux.
Here is a sample component:
import React, { Component } from 'react'
import { connect } from 'react-redux'
class Sample extends Component {
constructor(props) {
super(props);
this.state = {
...
}
}
componentDidMount() {
//do stuff
console.log(this.props)
}
render() {
const { user } = this.props
return(
<div className="sample">
{user.name}
</div>
)
}
}
const mapStateToProps = state => ({
user: state.user
})
export default connect(mapStateToProps, {})(Sample);
Here is a sample test:
import React from 'react';
import { createStore } from 'redux'
import { Provider } from 'react-redux'
import { render, cleanup } from 'react-testing-library';
import Sample from '../components/sample/'
const user = {
id: 1,
name: "John Smith"
}}
function reducer(state = user, action) {
//dont need any actions at the moment
switch (action.type) {
default:
return state
}
}
function renderWithRedux(
ui,
{ initialState, store = createStore(reducer, initialState) } = {}
) {
return {
...render(<Provider store={store}>{ui}</Provider>),
store,
}
}
afterEach(cleanup)
test('<Sample> example text', () => {
const { getByTestId, getByLabelText } = renderWithRedux(<Sample />)
expect(getByText(user.name))
})
The user prop value always results as undefined. I have re-written this a couple of ways but can't seem to get it to work. If I pass the user data directly as a prop to Sample component in the test, it still resolves to be undefined.
I am learning from the tutorials and examples via the offical docs, like this one: https://github.com/kentcdodds/react-testing-library/blob/master/examples/tests/react-redux.js
Any pointers, tips or solutions would be greatly appreciated!
You should wrap the component inside Provider, here is the simple example
import React from 'react';
import { render } from '#testing-library/react';
import '#testing-library/jest-dom';
import { Provider } from "react-redux";
import configureMockStore from "redux-mock-store";
import TestedComponent from '../index';
const mockStore = configureMockStore();
const store = mockStore({});
const renderTestedComponent = () => {
return render(
<Provider store={store}>
<TestedComponent />
</Provider>
);
};
describe('test TestedComponent components', () => {
it('should be render the component correctly', () => {
const { container } = renderTestedComponent();
expect(container).toBeInTheDocument();
});
});
**Unable to Fire event using #testing-library**
// demo.test.js
import React from 'react'
import { Provider } from "react-redux";
import '#testing-library/react/cleanup-after-each'
import '#testing-library/jest-dom/extend-expect'
import { render, fireEvent } from '#testing-library/react'
// this is used to fire the event
// import userEvent from "#testing-library/user-event";
//import 'jest-localstorage-mock';
import ChangePassword from './ChangePassword';
import configureMockStore from 'redux-mock-store';
import thunk from 'redux-thunk';
const middlewares = [thunk];
const mockStore = configureMockStore(middlewares);
test('test 1-> Update User password', () => {
// global store
const getState = {
authUser :{
user : {
email: "test#gmail.com",
id: 0,
imageURL: null,
name: "test Solutions",
roleId: 1,
roleName: "testRole",
userName: "testUserName"
},
loading: false,
showErrorMessage: false,
errorDescription: ""
}
}; // initial state of the store
// const action = { type: 'LOGIN_USER' };
// const expectedActions = [action];
// const store = mockStore(getState, expectedActions);
const onSaveChanges = jest.fn();
const changePassword = jest.fn();
const store = mockStore(getState);
const { queryByText, getByLabelText, getByText , getByTestId , getByPlaceholderText, } = render(
<Provider store={store}>
<ChangePassword
onSaveChanges={onSaveChanges}
changePassword={changePassword}
/>
</Provider>,
)
// test 1. check the title of component
expect(getByTestId('updateTitle')).toHaveTextContent('Update your password');
// test 2. chekck the inputfile
expect(getByPlaceholderText('Old Password')) //oldpassword
expect(getByPlaceholderText('New Password')) //newpassword
expect(getByPlaceholderText('Confirm New Password')) //confpassword
// change the input values
fireEvent.change(getByPlaceholderText("Old Password"), {
target: { value: "theOldPasword" }
});
fireEvent.change(getByPlaceholderText("New Password"), {
target: { value: "#Ab123456" }
});
fireEvent.change(getByPlaceholderText("Confirm New Password"), {
target: { value: "#Ab123456" }
});
// check the changed input values
expect(getByPlaceholderText('Old Password').value).toEqual("theOldPasword");
expect(getByPlaceholderText('New Password').value).toEqual("#Ab123456");
expect(getByPlaceholderText('Confirm New Password').value).toEqual("#Ab123456");
expect(getByText('Save Changes')); // check the save change button
// calling onSave function
//fireEvent.click(getByTestId('savechange'))
// userEvent.click(getByText('Save Changes'));
})

How to use React Native AsyncStorage with Redux?

I have made login and logout actions and userReducer. How can I integrate AsyncStorage with Redux? I am using Redux Thunk as a middleware.
I am able to implement login and logout using internal state variable but I am not able to understand how to break it down into action and reducer as well as make use of AsyncStorage for storing accessToken.
Original Code:
_onLogin = () => {
auth0.webAuth
.authorize({
scope: 'openid profile',
audience: 'https://' + credentials.domain + '/userinfo'
})
.then(credentials => {
this.setState({ accessToken: credentials.accessToken });
})
.catch(error => console.log(error));
};
_onLogout = () => {
if (Platform.OS === 'android') {
this.setState({ accessToken: null });
} else {
auth0.webAuth
.clearSession({})
.then(success => {
this.setState({ accessToken: null });
})
.catch(error => console.log(error));
}
};
loginAction.js:
import { LOGIN_USER } from './types';
import Auth0 from 'react-native-auth0';
var credentials = require('./auth0-credentials');
const auth0 = new Auth0(credentials);
export const loginUser = () => dispatch => {
auth0.webAuth
.authorize({
scope: 'openid profile',
audience: 'https://' + credentials.domain + '/userinfo'
})
.then(credentials =>
dispatch({
type: LOGIN_USER,
payload: credentials.accessToken
})
)
.catch(error => console.log(error));
}
logoutAction.js:
import { LOGOUT_USER } from './types';
import Auth0 from 'react-native-auth0';
var credentials = require('./auth0-credentials');
const auth0 = new Auth0(credentials);
export const logoutUser = () => dispatch => {
auth0.webAuth
.clearSession({})
.then(success =>
dispatch({
type: LOGOUT_USER,
payload: null
})
)
.catch(error => console.log(error));
}
userReducer.js:
import { LOGIN_USER, LOGOUT_USER } from '../actions/types';
const initialState = {
accessToken: null
}
export default function (state = initialState, action) {
switch (action.type) {
case LOGIN_USER:
_storeData = async () => {
try {
await AsyncStorage.setItem('accessToken', action.payload);
} catch (error) {
console.log(error)
}
}
return {
...state,
accessToken:action.payload
};
case LOGOUT_USER:
_removeData = async (accessToken) => {
try {
await AsyncStorage.removeItem(accessToken);
} catch (error) {
console.log(error)
}
}
return {
...state,
accessToken:action.payload
};
default:
return state;
}
}
I am new to Redux so I tried converting original code into actions and reducers but I am not sure whether I have implemented AsyncStorage in userReducer.js correctly?
To persist redux state I recommend you redux-persist.
Installation:
npm i -S redux-persist
Usage:
First, configure redux store
// configureStore.js
import { createStore } from 'redux'
import { persistStore, persistReducer } from 'redux-persist'
import storage from 'redux-persist/lib/storage' // defaults to localStorage for web and AsyncStorage for react-native
import rootReducer from './reducers'
const persistConfig = {
key: 'root',
storage,
}
const persistedReducer = persistReducer(persistConfig, rootReducer)
export default () => {
let store = createStore(persistedReducer)
let persistor = persistStore(store)
return { store, persistor }
}
Then, wrap your root component with PersistGate
import { PersistGate } from 'redux-persist/integration/react'
// ... normal setup, create store and persistor, import components etc.
const App = () => {
return (
<Provider store={store}>
<PersistGate loading={null} persistor={persistor}>
<RootComponent />
</PersistGate>
</Provider>
);
};
You can conveniently use AsyncStorage alone OR redux to manage authentication state. Depends on which you are comfortable with. I will give you an example of both.
For AsyncStorage:
Assuming you have authentication keys that is valid for 2 weeks only. You can take note when your user logs in and save the time. eg:
//LoginScreen
import { onSignIn } from '../actions/auth'; //I will describe the onSignInMethod below
import axios from 'axios'; //lets use axios. You may use fetch too.
export default class LoginScreen extends Component {
//your code: state, static etc
loginMethod = () => {
const url = yourauthUrl;
const payload = {
email: this.state.email,
password: this.state.password
};
axios.post(url, payload)
.then((response) => {
if (response.status == 200) {
const dateOfLastLogin = new Date().getTime().toString(); //take note of the time the user logs in.
AsyncStorage.setItem('dateOfLastLogin', dateOfLastLogin);
}
})
.then(() => {
onSignIn() //onSignIn handles your sign in. See below.
.then(() => this.props.navigation.navigate('AfterSignInPage'));
})
.catch(() => { // your callback if onSignIn Fails
});
})
.catch((error) => { //your callback if axios fails
});
}
}
In ../actions/auth.js
import { AsyncStorage } from 'react-native';
export const onSignIn = () => AsyncStorage.setItem('auth_key', 'true');
//in LoginScreen we called this to set that a user has successfully logged in
//why is true a string? -- Because Asyncstorage stores only strings
export const onSignOut = () => AsyncStorage.multiRemove(['auth_key', 'dateOfLastLogin']);
//now lets create a method that checks if the user is logged in anytime
export const isSignedIn = () => {
return new Promise((resolve, reject) => {
AsyncStorage.multiGet(['auth_key', 'dateOfLastLogin'])
.then((res) => {
const userKey = res[0][1];
const lastLoginDate = parseInt(res[1][1]);
const today = new Date().getTime();
const daysElapsed = Math.round(
(today - lastLoginDate) / 86400000
);
if (userKey !== null && (daysElapsed < 14)) {
resolve(true);
} else {
resolve(false);
}
})
.catch((err) => reject(err));
});
};
now we can import { isSignedIn } from '../actions/auth'; from any of our components and use it like this:
isSignedIn()
.then((res) => {
if (res) {
// user is properly logged in and the login keys are valid and less than 14 days
}
})
////////////////////////////////////////////////////////////////////////////
If you want to use redux
Handling login in redux
In your types.js
//types.js
export const LOGGED_IN = 'LOGGED_IN';
In your redux actions
//loginActions.js
import {
LOGGED_IN,
} from './types';
export function login() {
let dateOfLastLogin = null;
let isLoggedIn = 'false';
AsyncStorage.multiGet(['auth_key', 'dateOfLastLogin'])
.then((res) => {
isLoggedIn = res[0][1];
dateOfLastLogin = parseInt(res[1][1]);
}); //note this works asynchronously so, this may not be a good approach
return {
type: LOGGED_IN,
isLoggedIn,
dateOfLastLogin
};
}
In your loginReducer
//LoginReducer.js
import {
LOGGED_IN
} from '../actions/types';
const initialState = {
userIsLoggedIn: false
};
export function loginReducer(state=initialState, action) {
switch (action.type) {
case LOGGED_IN:
const userKey = action.isLoggedIn;
const lastLoginDate = action.dateOfLastLogin;
const today = new Date().getTime();
const daysElapsed = Math.round(
(today - lastLoginDate) / 86400000
);
let trulyLoggedIn = false;
if (userKey !== null && (daysElapsed < 14)) {
trulyLoggedIn = true;
} else { trulyLoggedIn = false }
return {
userIsLoggedIn: trulyLoggedIn
};
default:
return state;
}
}
In your ./reducers/index.js
//reducers index.js
import { combineReducers } from 'redux';
import { loginReducer } from './LoginReducers';
const rootReducer = combineReducers({
loggedIn: loginReducer
});
export default rootReducer;
In your store where you used redux-thunk, applyMiddleWare. Lets call it configureStore.js
//configureStore.js
import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import rootReducer from '../reducers';
export default function configureStore(initialState) {
return createStore(
rootReducer,
initialState,
applyMiddleware(thunk)
);
}
In your App.js
//App.js
import { Provider } from 'react-redux';
import configureStore from './src/store/configureStore'; //where you configured your store
import { YourMainNavigator } from '../src/config/router'; //where your root navigator is
const store = configureStore();
export default class App extends Component<{}> {
render() {
return (
<Provider store={store}>
<YourMainNavigator />
</Provider>
);
}
}
You should know you no longer need the isSignedIn method in your auth.js
Your login method remains the same as outlined above in LoginScreen.
Now you can use redux to check the state of login like this:
import React, {Component} from 'react';
import {connect} from 'react-redux';
class MyComponent extends Component {
someFunction() {
if (this.props.loggedIn) {
//do something
}
}
}
const mapStateToProps = (state) => {
return {
loggedIn: state.loggedIn.userIsLoggedIn
};
}
export default connect(mapStateToProps)(MyComponent);
There should be a better way of using redux to manage login - better than what I outlined here. I think you can also use redux to manage your login state without using AsyncStorage. All you need to do is in your loginScreen, if the login functions returns a response.status == 'ok', you can dispatch an action to redux that logs the user in. In the example above, using asyncstorage you might only need to use redux to check if a user is logged in.
It is recommended that you use an abstraction on top of AsyncStorage instead of AsyncStorage directly for anything more than light usage since it operates globally. Redux-persist is that abstraction that goes on top of AsyncStorage. It provides a better way to store and retrieve more complex data (e.g. redux-persist has persistReducer(), persistStore()).
React native typescript implementation
storage.ts
import AsyncStorage from "#react-native-community/async-storage";
import { createStore, combineReducers } from "redux";
import { persistStore, persistReducer } from "redux-persist";
import exampleReducer from "./example.reducer";
const rootReducer = combineReducers({
example: exampleReducer,
});
const persistConfig = {
key: "root",
storage: AsyncStorage,
whitelist: ["example"],
};
// Middleware: Redux Persist Persisted Reducer
const persistedReducer = persistReducer(persistConfig, rootReducer);
const store = createStore(persistedReducer);
// Middleware: Redux Persist Persister
let persistor = persistStore(store);
export { store, persistor };
App.tsx
import React from "react";
import { PersistGate } from "redux-persist/es/integration/react";
import { Provider } from "react-redux";
import RootNavigator from "./navigation/RootNavigator";
import { store, persistor } from "./store";
function App() {
return (
<Provider store={store}>
<PersistGate loading={null} persistor={persistor}>
<RootNavigator />
</PersistGate>
</Provider>
);
}
export default App;

Test connected component in React/Redux

I am trying test my connected component of my React/Redux app and I wrote some test case which actually throws the error:
App component › shows account info and debits and credits`
Invariant Violation: Could not find "store" in either the context or props of "Connect(AccountInfo)". Either wrap the root component in a <Provider>, or explicitly pass "store" as a prop to "Connect(AccountInfo)".
The test case which trow an error app.test.js is below. And my problem is that I don't understand what should I wrap here by Connect() because I didn't use AccountInfo here:
import React from 'react';
import { mount } from 'enzyme';
import { Provider } from 'react-redux';
import App from './App';
import * as actions from '../../actions';
function setup() {
const props = {
errorMessage: null,
actions
};
const enzymeWrapper = mount(<App {...props} />);
return {
props,
enzymeWrapper,
};
}
describe('App component', () => {
it('shows account info and debits and credits`', () => {
const {enzymeWrapper} = setup();
expect(enzymeWrapper.find('.account-info').exists()).toBe(true);
expect(enzymeWrapper.find('.debits-and-credits').exists()).toBe(true);
});
it('shows error message', () => {
const {enzymeWrapper} = setup();
enzymeWrapper.setProps({ errorMessage: 'Service Unavailable' });
expect(enzymeWrapper.find('.error-message').exists()).toBe(true);
});
});
My containers/app.js:
import { connect } from 'react-redux';
import { bindActionCreators } from 'redux';
import * as actions from '../actions';
import AppComponent from '../components/App/App';
const mapStateToProps = state => ({
isFetching: state.balance.isFetching,
errorMessage: state.errorMessage,
});
const mapDispatchToProps = dispatch => ({
actions: bindActionCreators(actions, dispatch),
});
const AppContainer = connect(mapStateToProps, mapDispatchToProps)(AppComponent);
export default AppContainer;
The component app.js:
import React, { Component } from 'react';
import ErrorMessage from '../../containers/ErrorMessage';
import AccountInfo from '../../containers/AccountInfo';
import DebitsAndCredits from '../../containers/DebitsAndCredits';
import './App.css';
const AppComponent = () =>
<div className="app">
<AccountInfo />
<DebitsAndCredits />
</div>;
export class App extends Component {
componentWillMount() {
const { actions } = this.props;
actions.fetchBalance();
}
render() {
const { errorMessage } = this.props;
return errorMessage ? <ErrorMessage /> : <AppComponent />;
}
}
export default App;
UPD:
I updated my test case and now it looks like:
import React from 'react';
import { mount } from 'enzyme';
import { Provider } from 'react-redux';
import configureMockStore from 'redux-mock-store';
import createSagaMiddleware from 'redux-saga';
import { initialState } from '../../reducers/balance/balance';
import App from './App';
import * as actions from '../../actions';
const middlewares = [createSagaMiddleware];
const mockStore = configureMockStore(middlewares);
const store = mockStore(initialState);
function setup() {
const props = {
errorMessage: null,
actions,
};
const enzymeWrapper = mount(
<Provider store={store}>
<App {...props} />
</Provider>
);
return {
props,
enzymeWrapper,
};
}
describe('App component', () => {
it('shows account info and debits and credits`', () => {
const { enzymeWrapper } = setup();
expect(enzymeWrapper.find('.account-info').exists()).toBe(true);
expect(enzymeWrapper.find('.debits-and-credits').exists()).toBe(true);
});
it('shows error message', () => {
const { enzymeWrapper } = setup();
enzymeWrapper.setProps({ errorMessage: 'Service Unavailable' });
expect(enzymeWrapper.find('.error-message').exists()).toBe(true);
});
});
And my error now is:
App component › shows account info and debits and credits`
TypeError: Cannot read property 'account' of undefined
UPD 2:
My initialState which I put when I create mocked store:
const initialState = {
isFetching: false,
account: {},
currency: '',
debitsAndCredits: [],
};
My AccountInfo component:
import React from 'react';
const AccountInfo = ({ account, currency }) =>
<header className="account-info">
<p>{account.name}</p>
<p>
IBAN: {account.iban}<br />
Balance: {account.balance}<br />
Currency: {currency}<br />
</p>
</header>;
export default AccountInfo;
For testing the connected component, you need to mock the provider as well, since the connect picks state variables from redux store.
Do this
const enzymeWrapper = mount (<Provider store={mockStore}><App {...props}/></Provider>)
You need to mock the redux store too.
Edit 1:
Just looking at your AccountInfo component it tells me that you are expecting account in the props here.
AccountInfo = ({account}) =>
So that means App.js has to pass down the accounts' value in the props. Same thing goes for currency.

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