Redux + storybook throws warning about changing store on the fly even with module.hot implemtended - react-redux

I'm using storybook and I want to add redux as decorator.
Whe running storybook, I got warning in console:
<Provider> does not support changing `store` on the fly. It is most likely that you see this error because you updated to Redux 2.x and React Redux 2.x which no longer hot reload reducers automatically. See https://github.com/reactjs/react-redux/releases/tag/v2.0.0 for the migration instructions.
It's my code for config storybook:
/* eslint-disable import/no-extraneous-dependencies, import/no-unresolved, import/extensions */
import React from 'react';
import { configure, storiesOf } from '#storybook/react';
import { Provider as ReduxProvider } from 'react-redux';
import forEach from 'lodash/forEach';
import unset from 'lodash/unset';
import Provider from 'components/Provider';
import initStore from 'utils/initStore';
import messages from '../lang/en.json';
const req = require.context('../components', true, /_stories\.js$/);
const ProviderDecorator = (storyFn) => {
const TheProvider = Provider(() => storyFn());
return (
<ReduxProvider store={initStore()}>
<TheProvider key={Math.random()} now={1499149917064} locale="en" messages={messages} />
</ReduxProvider>
);
}
function loadStories() {
req.keys().forEach((filename) => {
const data = req(filename);
if (data.Component !== undefined && data.name !== undefined && data.stories !== undefined) {
const Component = data.Component;
const stories = storiesOf(data.name, module);
stories.addDecorator(ProviderDecorator);
let decorator = data.stories.__decorator;
if (data.stories.__decorator !== undefined) {
stories.addDecorator((storyFn) => data.stories.__decorator(storyFn()));
}
forEach(data.stories, (el, key) => {
if (key.indexOf('__') !== 0) {
stories.add(key, () => (
<Component {...el} />
));
}
});
} else {
console.error(`Missing test data for ${filename}!`)
}
});
}
configure(loadStories, module);
and initStore file:
import { createStore, applyMiddleware } from 'redux';
import { composeWithDevTools } from 'redux-devtools-extension';
import thunkMiddleware from 'redux-thunk';
import { persistStore, autoRehydrate } from 'redux-persist';
import reducers from 'containers/redux/reducers';
export default () => {
const store = createStore(
reducers,
{},
composeWithDevTools(applyMiddleware(thunkMiddleware), autoRehydrate()),
);
if (module.hot) {
// Enable Webpack hot module replacement for reducers
module.hot.accept('../containers/redux/reducers', () => {
const nextReducers = require('../containers/redux/reducers'); // eslint-disable-line global-require
store.replaceReducer(nextReducers);
});
}
persistStore(store);
return store;
};
So as you can see I followed instructions from link in warning. What have I done wrong and how can I remove this warning? I know it won't show on production server, but it's pretty annoying in dev mode. :/

The reason this is happening has to do with the way Storybook hot-loads.
When you change your story, that module is hot-loaded, meaning that the code inside it is executed again.
Since you're using a store creator function and not a store instance from another module, the actual store object that is being passed to ReduxProvider on hot-load is new every time.
However, the React tree that is re-constructed is for the most part identical, meaning that the ReduxProvider instance is re-rendered with new props instead of being re-created.
Essentially, this is changing its store on the fly.
The solve is to make sure that ReduxProvider instance is new, too, on hot-load. This is easily solved by passing it a unique key prop, e.g.:
const ProviderDecorator = (storyFn) => {
const TheProvider = Provider(() => storyFn());
return (
<ReduxProvider key={Math.random()} store={initStore()}>
<TheProvider key={Math.random()} now={1499149917064} locale="en" messages={messages} />
</ReduxProvider>
);
}
From React Keys:
Keys help React identify which items have changed, are added, or are removed. Keys should be given to the elements inside the array to give the elements a stable identity.

Related

mqtt-react-hooks Subscriber stops working after one message

I have a simple react app using mqtt-react-hooks and redux. I want to update my redux store each time a new message is received by a Subscriber.
Subscriber.tsx
import React, { useEffect} from 'react';
import { useSubscription } from 'mqtt-react-hooks';
import { useAppDispatch } from '../features/item/hooks';
import { addItem } from '../features/item/item-slice';
const Subscriber = () => {
const { message } = useSubscription('queue');
const dispatch = useAppDispatch();
useEffect(() => {
if (message && message.message) {
dispatch(addItem(JSON.parse(message.message)));
}
}, [message]);
return (
<span>{message}</span>
);
};
export default Subscriber
App.tsx
import React from 'react';
import './App.css';
import {useAppSelector} from './features/item/hooks'
import { Connector } from 'mqtt-react-hooks'
import Subscriber from './mqtt/Subscriber'
function App() {
const items = useAppSelector((state) => state.item.items);
return (
<>
<Connector brokerUrl="ws://localhost:9001"
options={{keepalive: 10}}>
<div className="item-holder">
{Array.from(items, ([key, it]) => ({ key, it })).map( (kvp) => { return <div>{kvp.it} key={kvp.key}></div>})}
</div>
<Subscriber />
</Connector>
</>
);
}
export default App;
If I remove the useEffect from the Subscriber, the message gets received and updated. And I can send as many messages as I want. However, when I call the dispatch(addItem(... inside the useEffect, it will receive the first message, but ignores all future messages. My mosquitto broker says that the client has closed the connection. It never attempts to reconnect.
I'm very new to react. I have a feeling I'm not doing this right at all. What I really want is a redux store that maintains state based off of messages coming from an mqtt topic. The app has buttons that allows the user to publish messages back to the mqtt broker and change the redux state.
EDIT
As requested, here's the addItem code.
import {createSlice, PayloadAction} from '#reduxjs/toolkit'
interface ItemState {
items: Item[],
}
const initialState: ItemState = {
items: []
}
const orderSlice = createSlice({
name: 'items',
initialState,
reducers: {
addItem(state, action: PayloadAction<Item>) {
state.items.push(action.payload);
return state;
}
}
});
export const { addItem } = itemSlice.actions;
export default itemSlice.reducer;
And the useAppDispatch comes from ./features/item/hooks
import { TypedUseSelectorHook, useDispatch, useSelector } from "react-redux";
import { RootState, AppDispatch } from './item-store'
export const useAppDispatch = () => useDispatch<AppDispatch>();
export const useAppSelector: TypedUseSelectorHook<RootState> = useSelector;
However, I will add that I got rid of this and used the usual useDispatch and useSelector instead of the "useApp____" versions and got the same result.
I believe the issue lies in the mqtt-react-hooks hooks but my react-fu skills are not yet high enough to solve.
It looks like there is a sequence of things happening that is causing Connector to rerender and drop the connection, here's what I think is going on:
App is subscribing to store state, causing it to rerender every time a new message is received.
You're recreating your mqtt config object every time App renders, because you're passing an object literal {keepalive: 10}
In Connector.tsx line 48, the mqttConnect callback depends on the mqtt options object. React does a referential equality check, sees the options have changed, and causes the callback to be recreated.
In Connector.tsx line 59, this causes the useEffect to rerun because the callback changed, which calls its teardown function, which ends the mqtt connection.
To fix it, you should create your MQTT options outside of App so that they don't change.

Apollo Client reactive variable state is not kept in cache after refreshing the page

I have Apollo Client running on my React app, and trying to keep authentication info in a Reactive Variable using useReactiveVar. Everything works in the dummy function when I first set the variable, however it resets the state after refreshing the app.
Here's my cache.js:
import { InMemoryCache, makeVar } from "#apollo/client";
export const cache = new InMemoryCache({
typePolicies: {
Query: {
fields: {
isLoggedIn: {
read() {
return isLoggedInVar();
},
},
},
},
},
});
export const isLoggedInVar = makeVar();
export default cache;
Here's the component that reads the variable and renders different elements based on its state:
import React from "react";
import { useReactiveVar, useMutation } from "#apollo/client";
import MainButton from "../common/MainButton";
import { isLoggedInVar, userAddressVar } from "../../cache";
import { CREATE_OR_GET_USER } from "../../mutations/User";
const Profile = () => {
const isLoggedIn = useReactiveVar(isLoggedInVar);
const [createOrGetUser] = useMutation(CREATE_OR_GET_USER);
const handleCreateOrGetUser = () => {
const loginInput = {
address: 'text',
};
createOrGetUser({
variables: {
loginInput: loginInput,
},
}).then((res) => {
isLoggedInVar(true);
});
};
const profileComponent = isLoggedIn ? (
<div>Logged In</div>
) : (
<div onClick={handleCreateOrGetUser} className="profile-image"></div>
);
return (
<div className="profile-container">
{profileComponent}
</div>
);
};
export default Profile;
This component gets re-rendered properly when I invoke handleCreateOrGetUser, however, when I refresh the page, it resets the isLoggedInVar variable.
What would be the proper way to use Reactive Variables here to persist the cache?
It's not currently achievable using Apollo API according to their documentation.
There is currently no built-in API for persisting reactive variables,
but you can write variable values to localStorage (or another store)
whenever they're modified, and initialize those variables with their
stored value (if any) on app load.
There is a PR for that. https://github.com/apollographql/apollo-client/pull/7148

ReduxForm is rendered twice when mounted via enzyme

I'm trying to align my tests to follow breaking changes after upgrading react-redux to 6.0.0 and redux-form to 8.1.0 (connected components do not take store in props any longer)
I needed to wrap my connected component in from react-redux in tests and use mount to get to actual component but now ReduxForm is rendered twice.
I tried to use hostNodes() method but it returns 0 elements.
Any ideas how to fix it?
Here is the test:
import React from 'react'
import { mount } from 'enzyme'
import configureStore from 'redux-mock-store'
import { Provider } from 'react-redux'
import PasswordResetContainer from './PasswordResetContainer'
describe('PasswordResetContainer', () => {
it('should render only one ReduxForm', () => {
const mockStore = configureStore()
const initialState = {}
const store = mockStore(initialState)
const wrapper = mount(<Provider store={store}><PasswordResetContainer /></Provider>)
const form = wrapper.find('ReduxForm')
console.log(form.debug())
expect(form.length).toEqual(1)
})
And PasswordResetContainer looks like this:
import { connect } from 'react-redux'
import { reduxForm } from 'redux-form'
import PasswordReset from './PasswordReset'
import { resetPassword } from '../Actions'
export const validate = (values) => {
const errors = {}
if (!values.email) {
errors.email = 'E-mail cannot be empty.'
} else if (!/^[A-Z0-9._%+-]+#[A-Z0-9.-]+\.[A-Z]{2,4}$/i.test(values.email)) {
errors.email = 'Invalid e-mail.'
}
return errors
}
export default connect(null, { resetPassword })(
reduxForm(
{ form: 'passwordReset',
validate
})(PasswordReset))
Output from test is following:
PasswordResetContainer › should render only one ReduxForm
expect(received).toEqual(expected)
Expected value to equal:
1
Received:
2
Edit (partial solution found):
When I changed wrapper.find('ReduxForm')
into wrapper.find('ReduxForm>Hoc>ReduxForm') it started to work.
Why do I need to do such a magic?
A fix is on library mods to create but if the forms are identical, one quick way to get around the issue is to call first() after find so that
wrapper.find('ReduxForm')
looks like:
wrapper.find('ReduxForm').first()

React-Redux re-render on dispatch inside HOC not working

I am busy with a little proof of concept where basically the requirement is to have the home page be a login screen when a user has not logged in yet, after which a component with the relevant content is shown instead when the state changes upon successful authentication.
I have to state upfront that I am very new to react and redux and am busy working through a tutorial to get my skills up. However, this tutorial is a bit basic in the sense that it doesn't deal with connecting with a server to get stuff done on it.
My first problem was to get props to be available in the context of the last then of a fetch as I was getting an error that this.props.dispatch was undefined. I used the old javascript trick around that and if I put a console.log in the final then, I can see it is no longer undefined and actually a function as expected.
The problem for me now is that nothing happens when dispatch is called. However, if I manually refresh the page it will display the AuthenticatedPartialPage component as expected because the localstorage got populated.
My understanding is that on dispatch being called, the conditional statement will be reavaluated and AuthenticatedPartialPage should display.
It feels like something is missing, that the dispatch isn't communicating the change back to the parent component and thus nothing happens. Is this correct, and if so, how would I go about wiring up that piece of code?
The HomePage HOC:
import React from 'react';
import { createStore, combineReducers } from 'redux';
import { connect } from 'react-redux';
import AuthenticatedPartialPage from './partials/home-page/authenticated';
import AnonymousPartialPage from './partials/home-page/anonymous';
import { loggedIntoApi, logOutOfApi } from '../actions/authentication';
import authReducer from '../reducers/authentication'
// unconnected stateless react component
const HomePage = (props) => (
<div>
{ !props.auth
? <AnonymousPartialPage />
: <AuthenticatedPartialPage /> }
</div>
);
const mapStateToProps = (state) => {
const store = createStore(
combineReducers({
auth: authReducer
})
);
// When the user logs in, in the Anonymous component, the local storage is set with the response
// of the API when the log in attempt was successful.
const storageAuth = JSON.parse(localStorage.getItem('auth'));
if(storageAuth !== null) {
// Clear auth state in case local storage has been cleaned and thus the user should not be logged in.
store.dispatch(logOutOfApi());
// Make sure the auth info in local storage is contained in the state.auth object.
store.dispatch(loggedIntoApi(...storageAuth))
}
return {
auth: state.auth && state.auth.jwt && storageAuth === null
? state.auth
: storageAuth
};
}
export default connect(mapStateToProps)(HomePage);
with the Anonymous LOC being:
import React from 'react';
import { connect } from 'react-redux';
import { Link } from 'react-router-dom';
import { loggedIntoApi } from '../../../actions/authentication';
export class AnonymousPartialPage extends React.Component {
constructor(props) {
super(props);
}
onSubmit = (e) => {
e.preventDefault();
const loginData = { ... };
// This is where I thought the problem initially occurred as I
// would get an error that `this.props` was undefined in the final
// then` of the `fetch`. After doing this, however, the error went
// away and I can see that `props.dispatch is no longer undefined
// when using it. Now though, nothing happens.
const props = this.props;
fetch('https://.../api/auth/login', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify(loginData)
})
.then(function(response) {
return response.json();
})
.then(function(data) {
if(data && data.jwt) {
props.dispatch(loggedIntoApi(data));
localStorage.setItem('auth', JSON.stringify(data));
}
// else show an error on screen
});
};
render() {
return (
<div>
... onSubmit gets called successfully somewhere in here ...
</div>
);
}
}
export default connect()(AnonymousPartialPage);
the action:
// LOGGED_INTO_API
export const loggedIntoApi = (auth_token) => ({
type: 'LOGGED_INTO_API',
auth: auth_token
});
// LOGGED_OUT_OF_API
export const logOutOfApi = (j) => ({
type: 'LOG_OUT_OF_API'
});
and finally the reducer:
const authDefaultState = { };
export default (state = authDefaultState, action) => {
switch (action.type) {
case 'LOGGED_INTO_API':
// SOLUTION : changed this line "return action.auth;" to this:
return { ...action.auth, time_stamp: new Date().getTime() }
case 'LOG_OUT_OF_API':
return { auth: authDefaultState };
default:
return state;
}
};
My suggestion would be to make sure that the state that you are changing inside Redux is changing according to javascript's equality operator!. There is a really good answer to another question posted that captures this idea here. Basically, you can't mutate an old object and send it back to Redux and hope it will re-render because the equality check with old object will return TRUE and thus Redux thinks that nothing changed! I had to solve this issue by creating an entirely new object with the updated values and sending it through dispatch().
Essentially:
x = {
foo:bar
}
x.foo = "baz"
dispatch(thereWasAChange(x)) // doesn't update because the x_old === x returns TRUE!
Instead I created a new object:
x = {
foo:"bar"
}
y = JSON.parse(JSON.stringify(x)) // creates an entirely new object
dispatch(thereWasAChange(y)) // now it should update x correctly and trigger a rerender
// BE CAREFUL OF THE FOLLOWING!
y = x
dispatch(thereWasAChange(y)) // This WON'T work!!, both y and x reference the SAME OBJECT! and therefore will not trigger a rerender
Hope this helps!

Using Redux-Persist with Baqend React/Redux Starter

Does anyone know how to add redux-persist https://github.com/rt2zz/redux-persist
to the store from the starter kit: https://www.baqend.com/guide/starter-kits/react/
import { applyMiddleware, combineReducers } from 'redux'
import { createStoreWithBaqend, baqendReducer } from 'redux-baqend'
import middlewares from '../middleware'
import reducers from '../reducers'
import { db } from 'baqend'
export default (initialState = {}) => {
const reducer = combineReducers({
baqend: baqendReducer,
...reducers
})
const middleware = applyMiddleware(
...middlewares
)
return createStoreWithBaqend(
db.connect('remarkable-apple-XX', true),
reducer,
initialState,
middleware
)
}
I haven't tried this myself yet, but the documentation from redux-persist looks like you just add the autoRehydrate and wrap the created store in the persistStore method. The createStoreWithBaqend method is basically the same like the normal createStore method, but adds some baqend specific stuff to your store.
I would try it like this:
export default (initialState = {}) => {
const reducer = combineReducers({
baqend: baqendReducer,
...reducers
})
const middleware = applyMiddleware(
...middlewares
)
const store = createStoreWithBaqend(
db.connect('remarkable-apple-XX', true),
reducer,
initialState,
compose(
middleware,
autoRehydrate()
)
)
return persistStore(store)
}
Remember to import compose from the redux library. Hope this helps.

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