Develop Reference

Writing Enzyme Unit Test cases of Idle Time Container

Currently I am trying to write TC for a function that is idle Time out Container
I am able to get 50 % coverage but nnote able to target the custom function can any one help me out
My Function
const IdleTimeoutContainer = props => {
const { logoutUser, usrProfId } = props;
const timeout = 1000 * 20;
const promptTimeout = 1000 * 60;
const userProfileID = usrProfId;
const [open, setOpen] = useState(false);
const [promptRemainingTimeout, setPromptRemainingTimeout] = useState(60);
const [remaining, setRemaining] = useState(0);
const onPrompt = () => {
setOpen(true);
setRemaining(promptTimeout);
setPromptRemainingTimeout(60);
};
const onIdle = () => {
setOpen(false);
setRemaining(0);
toastFunc({
content: 'Logged Off due to Idle Time',
config: { className: 'toast-container reject' },
toastType: 'error'
});
logoutUser();
};
const onActive = () => {
setOpen(false);
setRemaining(0);
};
const { getRemainingTime, isPrompted, activate } = useIdleTimer({
timeout,
promptTimeout,
onPrompt,
onIdle,
onActive
});
const handleStillHere = () => {
extendSessionApi()
.then(() => {
setOpen(false);
activate();
})
.catch(err => {
setOpen(false);
if (err.response.status) {
toastFunc({
content: err.response.data.errorMessage,
config: { className: 'toast-container reject' },
toastType: 'error'
});
logoutUser();
}
});
};
const handleLogOff = () => {
setOpen(false);
toastFunc({
content: 'Logged Off',
config: { className: 'toast-container reject' },
toastType: 'error'
});
logoutUser();
};
useEffect(() => {
const interval = setInterval(() => {
if (isPrompted()) {
setRemaining(Math.ceil(getRemainingTime() / 1000));
setPromptRemainingTimeout(Math.ceil(promptRemainingTimeout - 1));
}
}, 1000);
return () => {
clearInterval(interval);
};
}, [getRemainingTime, isPrompted, promptRemainingTimeout]);
return (
<div data-test='idle-timeout-container'>
{userProfileID && (
<Modal
data-test='idle-timeout-modal'
isOpen={open}
submitBtnLabel='Log-off'
onSubmit={handleLogOff}
cancelBtnLabel='Keep me Logged-in'
onCancel={handleStillHere}
>
<div className='circularProgressWithLabel'>
<span>
Are You Still There? Your session is about to expire due to <br />
inactivity in approximately {promptRemainingTimeout} seconds.
</span>
<Box position='relative' display='inline-flex'>
<CircularProgress
variant='static'
size={100}
thickness={5}
color='primary'
value={(promptRemainingTimeout / 60) * 100}
/>
<Box
top={0}
left={0}
bottom={0}
right={0}
position='absolute'
display='flex'
alignItems='center'
justifyContent='center'
>
<Typography variant='h2' component='div' color='primary'>
<b>{`${promptRemainingTimeout}`}</b>
</Typography>
</Box>
</Box>
</div>
</Modal>
)}
</div>
);
};
export default IdleTimeoutContainer;
test case file
const setup = (props = {}) => {
return shallow(<IdleTimeoutContainer {...props} />);
};
describe('Should render idle-timeout-container correctly ', () => {
let wrapper;
let onCancel;
let onConfirm;
let props;
beforeEach(() => {
const props = {
getUser: jest.fn,
logoutUser: jest.fn,
usrProfId: '1234',
submitBtnLabel:'Log-off',
cancelBtnLabel:'Keep me Logged-in',
onCancel,
onConfirm
};
wrapper = setup(props);
});
it('should render idle-timeout-container', () => {
const component = findComponentByTestAttr(
wrapper,
'idle-timeout-container'
);
expect(component).toHaveLength(1);
});
it('should render idle-timeout-modal', () => {
const component = findComponentByTestAttr(wrapper, 'idle-timeout-modal');
expect(component).toHaveLength(1);
});
it('should render idle-timeout-modalcontainer', () => {
const component = findComponentByTestAttr(wrapper, 'idle-timeout-modal');
component.simulate('submit');
expect(onConfirm);
});
it('should render idle-timeout-modalcontainer', () => {
const component = findComponentByTestAttr(wrapper, 'idle-timeout-modal');
component.simulate('cancel');
expect(onCancel);
});
});
i am not able to cover the TC before the Return, as it is custom code, can anyone help me please need to learn aleast one so that I can work it out

useState defaults appear to rerun after running function on state change, defaults shouldnt run twice

I have the following issue with website where the settings state resets after running more searches. The settings component is show below in the picture, it usually works but if you uncheck a box and then run a few more searches at some point the showAllDividends setting will be set to false, the All dividends component won't be on the screen, but for some reason the checkbox itself is checked (true). This is my first time really working with checkboxes in React, and I think I'm using the onChange feature wrong. Right now I get the event.target.checked boolean, but only onChange.
If that isn't the issue then the most likely cause is the default statements being run again on another render:
const [showMainInfo, setShowMainInfo] = useState(true);
const [showYieldChange, setShowYieldChange] = useState(true);
const [showAllDividends, setShowAllDividends] = useState(true);
the thing is I don't see why the default statements would run more than once, the component isn't being destroyed there's no react router usage. I expected it to keep its current state after the page is first loaded. I think the settings defaults are being rerun, but just don't understand why they would.
I unchecked, checked, unchecked the 'All dividends' checkbox, and it was unchecked when I ran 2 more searches. After the second search the checkbox was checked but the component was gone, because showAllDividends was false
main component SearchPage.js:
import React, {useState, useEffect} from 'react';
import { connect } from 'react-redux';
import axios from 'axios';
import SearchBar from './SearchBar';
import AllDividendsDisplay from './dividend_results_display/AllDividendsDisplay';
import DividendResultsDisplay from './dividend_results_display/DividendResultsDisplay';
import SettingsView from './settings/SettingsView';
const HOST = process.env.REACT_APP_HOSTNAME
const PROTOCOL = process.env.REACT_APP_PROTOCOL
const PORT = process.env.REACT_APP_PORT
const BASE_URL = PROTOCOL + '://' + HOST + ':' + PORT
const SearchPage = ({userId}) => {
const DEFAULT_STOCK = 'ibm';
const [term, setTerm] = useState(DEFAULT_STOCK);
const [debouncedTerm, setDebouncedTerm] = useState(DEFAULT_STOCK);
const [loading, setLoading] = useState(false);
const [recentSearches, setRecentSearches] = useState([DEFAULT_STOCK]);
const [dividendsYearsBack, setDividendsYearsBack] = useState('3');
const [debouncedDividendYearsBack, setDebouncedDividendYearsBack] = useState('3');
const [errorMessage, setErrorMessage] = useState('');
const [dividendsData, setDividendsData] = useState(
{
current_price: '',
recent_dividend_rate: '',
current_yield: '',
dividend_change_1_year: '',
dividend_change_3_year: '',
dividend_change_5_year: '',
dividend_change_10_year: '',
all_dividends: [],
name: '',
description: '',
}
)
const [settingsViewVisible, setSettingsViewVisible] = useState(false);
const [showMainInfo, setShowMainInfo] = useState(true);
const [showYieldChange, setShowYieldChange] = useState(true);
const [showAllDividends, setShowAllDividends] = useState(true);
const onTermUpdate = (term) => {
setTerm(term)
}
// TODO: write a custom hook that debounces taking the term and the set debounced term callback
useEffect(() => {
const timerId = setTimeout(() => {
setDebouncedTerm(term);
}, 1500);
return () => {
clearTimeout(timerId);
};
}, [term]);
useEffect(() => {
const timerId = setTimeout(() => {
setDebouncedDividendYearsBack(dividendsYearsBack);
}, 1500);
return () => {
clearTimeout(timerId);
};
}, [dividendsYearsBack]);
useEffect(() => {runSearch()}, [debouncedTerm]);
useEffect(() => {
// alert(dividendsYearsBack)
if (dividendsYearsBack !== '') {
runSearch();
}
}, [debouncedDividendYearsBack])
useEffect(() => {
console.log("user id changed")
if (userId) {
const user_profile_api_url = BASE_URL + '/users/' + userId
axios.get(user_profile_api_url, {})
.then(response => {
const recent_searches_response = response.data.searches;
const new_recent_searches = [];
recent_searches_response.map(dict => {
new_recent_searches.push(dict.search_term)
})
setRecentSearches(new_recent_searches);
})
.catch((error) => {
console.log("error in getting user profile: ", error.message)
})
}
}, [userId])
useEffect(() => {
const user_profile_api_url = BASE_URL + '/users/' + userId
const request_data = {searches: recentSearches}
axios.post(user_profile_api_url, request_data)
// .then(response => {
// console.log(response)
// })
}, [recentSearches])
const makeSearchApiRequest = () => {
let dividends_api_url = BASE_URL + '/dividends/' + term + '/' + dividendsYearsBack
if (!recentSearches.includes(term)) {
setRecentSearches([...recentSearches, term])
}
axios.get(dividends_api_url, {})
.then(response => {
// console.log(response)
setLoading(false);
setDividendsData(response.data);
})
.catch((error) => {
console.log(error.message);
setLoading(false);
setErrorMessage(error.message);
})
}
const runSearch = () => {
console.log("running search: ", term);
setErrorMessage('');
if (term) {
setLoading(true);
if (!dividendsYearsBack) {
setDividendsYearsBack('3', () => {
makeSearchApiRequest()
});
} else {
makeSearchApiRequest()
}
}
}
const recentSearchOnClick = (term) => {
setTerm(term);
setDebouncedTerm(term);
}
const removeRecentSearchOnClick = (term) => {
const searchesWithoutThisOne = recentSearches.filter(search => search !== term)
setRecentSearches(searchesWithoutThisOne);
}
const dividendsYearsBackOnChange = (text) => {
setDividendsYearsBack(text);
}
const renderMainContent = () => {
if (!debouncedTerm) {
return (
<div className="ui active">
<div className="ui text">Search for info about a stock</div>
</div>
)
}
if (loading === true) {
return (
<div className="ui active dimmer">
<div className="ui big text loader">Loading</div>
</div>
)
}
if (errorMessage) {
return (
<div className="ui active">
<div className="ui text">{errorMessage}</div>
</div>
)
} else {
return (
<DividendResultsDisplay
data={dividendsData}
dividends_years_back={dividendsYearsBack}
dividendsYearsBackOnChange={dividendsYearsBackOnChange}
showMainInfo={showMainInfo}
showYieldChange={showYieldChange}
showAllDividends={showAllDividends}/>
)
}
}
// https://stackoverflow.com/questions/38619981/how-can-i-prevent-event-bubbling-in-nested-react-components-on-click
const renderRecentSearches = () => {
return recentSearches.map((term) => {
return (
<div key={term}>
<button
onClick={() => recentSearchOnClick(term)}
style={{marginRight: '10px'}}
>
<div>{term} </div>
</button>
<button
onClick={(event) => {event.stopPropagation(); removeRecentSearchOnClick(term)}}>
X
</button>
<br/><br/>
</div>
)
})
}
const renderSettingsView = (data) => {
if (settingsViewVisible) {
return (
<SettingsView data={data} />
)
} else {
return null;
}
}
const toggleSettingsView = () => {
setSettingsViewVisible(!settingsViewVisible);
}
const toggleDisplay = (e, setter) => {
setter(e.target.checked)
}
const SETTINGS_DATA = [
{
label: 'Main info',
id: 'main_info',
toggler: toggleDisplay,
setter: setShowMainInfo
},
{
label: 'Yield change',
id: 'yield_change',
toggler: toggleDisplay,
setter: setShowYieldChange
},
{
label: 'Dividends list',
id: 'all_dividends',
toggler: toggleDisplay,
setter: setShowAllDividends
},
]
console.log("showMainInfo: ", showMainInfo);
console.log("showYieldChange: ", showYieldChange);
console.log("showAllDividends: ", showAllDividends);
return (
<div className="ui container" style={{marginTop: '10px'}}>
<SearchBar term={term} onTermUpdate={onTermUpdate} />
{renderRecentSearches()}
<br/><br/>
<button onClick={toggleSettingsView}>Display settings</button>
{renderSettingsView(SETTINGS_DATA)}
<div className="ui segment">
{renderMainContent()}
</div>
</div>
)
}
const mapStateToProps = state => {
return { userId: state.auth.userId };
};
export default connect(
mapStateToProps
)(SearchPage);
// export default SearchPage;
the settingsView component:
import React from 'react';
import SettingsCheckbox from './SettingsCheckbox';
const SettingsView = ({data}) => {
const checkboxes = data.map((checkbox_info) => {
return (
<div key={checkbox_info.id}>
<SettingsCheckbox
id={checkbox_info.id}
label={checkbox_info.label}
toggler={checkbox_info.toggler}
setter={checkbox_info.setter}/>
<br/>
</div>
)
});
return (
<div className="ui segment">
{checkboxes}
</div>
);
}
export default SettingsView;
SettingsCheckbox.js:
import React, {useState} from 'react';
const SettingsCheckbox = ({id, label, toggler, setter}) => {
const [checked, setChecked] = useState(true)
return (
<div style={{width: '200px'}}>
<input
type="checkbox"
checked={checked}
id={id}
name={id}
value={id}
onChange={(e) => {
setChecked(!checked);
toggler(e, setter);
}} />
<label htmlFor="main_info">{label}</label><br/>
</div>
);
}
export default SettingsCheckbox;

InvalidStateError: Failed to execute 'send' on 'WebSocket': Still in CONNECTING state

I got an error for connecting WebSocket but i cant fix it, what is my codes problem?
When my page loads, I try to send a message, (also i wait a few seconds) but it's not working.
i used this method webSocket.current.readyState === WebSocket.OPEN but doesn't answered!!
My code:
export default function ChatRoom() {
const [input, setInput] = useState("");
const handleChange = (e) => setInput(e.target.value);
const handleOnEnter = (e) => {
if (e.charCode === 13 || e.which === 13) {
sendMessage();
setInput("");
}
};
const webSocket = useRef(null);
const [chatMessages, setChatMessages] = useState([]);
useEffect(() => {
console.log("Opening WebSocket");
webSocket.current = new WebSocket("ws://localhost:3000");
const openWebSocket = () => {
webSocket.current.onopen = (event) => {
console.log("Open:", event);
};
webSocket.current.onclose = (event) => {
console.log("Close:", event);
};
};
openWebSocket();
return () => {
console.log("Closing WebSocket");
webSocket.current.close();
};
}, []);
useEffect(() => {
webSocket.current.onmessage = (event) => {
const chatMessageDto = JSON.parse(event.data);
console.log("Message:", chatMessageDto);
setChatMessages([
...chatMessages,
{
content: input,
},
]);
};
}, [chatMessages]);
const sendMessage = () => {
console.log("WebSocket.OPEN === ", WebSocket.OPEN);
console.log("webSocket.current.readyState === ", webSocket.current.readyState);
if (webSocket.current.readyState === WebSocket.OPEN) {
console.log("Send!");
webSocket.current.send(
JSON.stringify({
content: input,
})
);
} else if (webSocket.current.readyState === WebSocket.CONNECTING) {
webSocket.current.addEventListener("open", () => sendMessage());
}
};
return (
<div className={styles.chatWrapper}>
</div>
<div>
{chatMessages.map((item) => (
<div>{item.content}</div>
))}
</div>
)}
<div>
<input
value={input}
placeholder={"type message ..."}
onChange={(e) => handleChange(e)}
onKeyPress={handleOnEnter}
/>
</div>
</div>
);
}
my console :
WebSocket.OPEN === 1
webSocket.current.readyState === 0

How to avoid prop drilling ? / How to use useContext?

I'm working on a React Notes Application and my App.js contains all the necessary functions props which are passed down to several components.
As a result I'm doing prop drilling a lot where I'm passing down around 10-20 props/functions in the components where it isn't needed.
I tried using useContext Hook but I guess it doesn't work with callback functions in the value parameter.
App.js
const App = () => {
const [ notes, setNotes ] = useState([]);
const [ category, setCategory ] = useState(['Notes']);
const [ searchText, setSearchText ] = useState('');
const [ alert, setAlert ] = useState({
show:false,
msg:'',
type:''
});
const [isEditing, setIsEditing] = useState(false);
const [editId, setEditId] = useState(null);
useEffect(()=>{
keepTheme();
})
// retreive saved notes
useEffect(()=>{
const savedNotes = JSON.parse(localStorage.getItem('react-notes-data'));
if (savedNotes) {
setNotes(savedNotes)
}
}, []);
// save notes to local storage
useEffect(() => {
localStorage.setItem('react-notes-data', JSON.stringify(notes))
setNotesCopy([...notes]);
}, [notes]);
// save button will add new note
const addNote = (text) => {
const date = new Date();
const newNote = {
id: nanoid(),
text: text,
date: date.toLocaleDateString(),
category: category,
}
const newNotes = [...notes, newNote]
setNotes(newNotes);
}
const deleteNote = (id) => {
showAlert(true, 'Note deleted', 'warning');
const newNotes = notes.filter(note => note.id !== id);
setNotes(newNotes);
}
// hardcoded values for categories
const allCategories = ['Notes', 'Misc', 'Todo', 'Lecture Notes', 'Recipe'];
// copy notes for filtering through
const [notesCopy, setNotesCopy] = useState([...notes]);
const handleSidebar = (category) => {
setNotesCopy(category==='Notes'?[...notes]:
notes.filter(note=>note.category===category));
}
// function to call alert
const showAlert = (show=false, msg='', type='') => {
setAlert({show, msg, type});
}
return (
<div>
<div className="container">
<Sidebar
allCategories={allCategories}
handleSidebar={handleSidebar}
notesCopy={notesCopy}
key={notes.id}
/>
<Header notes={notes} alert={alert} removeAlert={showAlert} />
<Search handleSearchNote={setSearchText} />
<NotesList
notesCopy={notesCopy.filter(note=>
note.text.toLowerCase().includes(searchText) ||
note.category.toString().toLowerCase().includes(searchText)
)}
handleAddNote={addNote}
deleteNote={deleteNote}
category={category}
setCategory={setCategory}
allCategories={allCategories}
showAlert={showAlert}
notes={notes}
setNotes={setNotes}
editId={editId}
setEditId={setEditId}
isEditing={isEditing}
setIsEditing={setIsEditing}
/>
</div>
</div>
)
}
NotesList.js
const NotesList = (
{ notesCopy, handleAddNote, deleteNote, category, setCategory, showHideClassName, allCategories, showAlert, isEditing, setIsEditing, notes, setNotes, editId, setEditId }
) => {
const [ noteText, setNoteText ] = useState('');
const textareaRef = useRef();
// function to set edit notes
const editItem = (id) => {
const specificItem = notes.find(note=>note.id === id);
setNoteText(specificItem.text);
setIsEditing(true);
setEditId(id);
textareaRef.current.focus();
}
return (
<div key={allCategories} className="notes-list">
{notesCopy.map(note => {
return (
<Note
key={note.id}
{...note}
deleteNote={deleteNote}
category={note.category}
isEditing={isEditing}
editId={editId}
editItem={editItem}
/>)
})}
<AddNote
handleAddNote={handleAddNote}
category={category}
setCategory={setCategory}
showHideClassName={showHideClassName}
allCategories={allCategories}
showAlert={showAlert}
isEditing={isEditing}
setIsEditing={setIsEditing}
notes={notes}
setNotes={setNotes}
editId={editId}
setEditId={setEditId}
noteText={noteText}
setNoteText={setNoteText}
textareaRef={textareaRef}
/>
</div>
)
}
AddNote.js
const AddNote = ({ notes, setNotes, handleAddNote, category, setCategory, showHideClassName, allCategories, showAlert, isEditing, setIsEditing, editId, setEditId, noteText, setNoteText, textareaRef }) => {
const [ show, setShow ] = useState(false);
const [ modalText, setModalText ] = useState('');
const charCount = 200;
const handleChange = (event) => {
if (charCount - event.target.value.length >= 0) {
setNoteText(event.target.value);
}
}
const handleSaveClick = () => {
if (noteText.trim().length === 0) {
setModalText('Text cannot be blank!');
setShow(true);
}
if (category === '') {
setModalText('Please select a label');
setShow(true);
}
if (noteText.trim().length > 0 && category!=='') {
showAlert(true, 'Note added', 'success');
handleAddNote(noteText);
setNoteText('');
setShow(false);
}
if (noteText.trim().length > 0 && category!=='' && isEditing) {
setNotes(notes.map(note=>{
if (note.id === editId) {
return ({...note, text:noteText, category:category})
}
return note
}));
setEditId(null);
setIsEditing(false);
showAlert(true, 'Note Changed', 'success');
}
}
const handleCategory = ( event ) => {
let { value } = event.target;
setCategory(value);
}
showHideClassName = show ? "modal display-block" : "modal display-none";
return (
<div className="note new">
<textarea
cols="10"
rows="8"
className='placeholder-dark'
placeholder="Type to add a note.."
onChange={handleChange}
value={noteText}
autoFocus
ref={textareaRef}
>
</textarea>
<div className="note-footer">
<small
className='remaining'
style={{color:(charCount - noteText.length == 0) && '#c60000'}}>
{charCount - noteText.length} remaining</small>
<div className='select'>
<select
name={category}
className="select"
onChange={(e)=>handleCategory(e)}
required
title='Select a label for your note'
defaultValue="Notes"
>
<option value="Notes" disabled selected>Categories</option>
{allCategories.map(item => {
return <option key={item} value={item}>{item}</option>
})}
</select>
</div>
<button className='save' onClick={handleSaveClick} title='Save note'>
<h4>{isEditing ? 'Edit':'Save'}</h4>
</button>
</div>
{/* Modal */}
<main>
<div className={showHideClassName}>
<section className="modal-main">
<p className='modal-text'>{modalText}</p>
<button type="button" className='modal-close-btn'
onClick={()=>setShow(false)}><p>Close</p>
</button>
</section>
</div>
</main>
</div>
)
}
I want the functions passed from App.js to NotesList.js to be in AddNote.js without them being passed in NotesList.js basically minimizing the props destructuring in NotesList.js

Context API does work with function. What you need to do is pass your function to Provider inside value :
<MyContext.Provider value={{notes: notesData, handler: myFunction}} >
For example:
// notes-context.js
import React, { useContext, createContext } from 'react';
const Context = createContext({});
export const NotesProvider = ({children}) => {
const [notes, setNote] = useState([]);
const addNote = setNote(...); // your logic
const removeNote = setNote(...); // your logic
return (
<Context.Provider value={{notes, addNote, removeNote}}>
{children}
</Context.Provider>
)
}
export const useNotes = () => useContext(Context);
Add Provider to your App.js like so:
// App.js
import NoteProvider from './notes-context';
export default App = () => {
return (
<NoteProvider>
<div>... Your App</div>
</NoteProvider>
)
}
Then call UseNote in your NoteList.js to use the function:
// NoteList.js
import {useNotes} from './note-context.js';
export const NoteList = () => {
const {notes, addNotes, removeNotes} = useNotes();
// do your stuff. You can now use functions addNotes and removeNotes without passing them down the props
}

Get an Error that .filter is not a function

I have tried to create an autocomplete suggestion box from an Thailand's province database URL.
This is my source code. I export this to App.js in src directory
import React, { useEffect, useState, useRef } from "react";
const Test = () => {
const [display, setDisplay] = useState(false);
const [singleProvince, setSingleProvince] = useState([]);
const [singleProvinceData, setSingleProvinceData] = useState([]);
const [search, setSearch] = useState("");
const wrapperRef = useRef(null);
const province_dataBase_url = 'https://raw.githubusercontent.com/earthchie/jquery.Thailand.js/master/jquery.Thailand.js/database/raw_database/raw_database.json'
useEffect(() => {
const promises = new Array(20).fill(fetch(province_dataBase_url)
.then((res) => {
return res.json().then((data) => {
const createSingleProvince = data.filter( (each) => {
if (false == (singleProvince.includes(each.province))) {
setSingleProvince(singleProvince.push(each.province))
setSingleProvinceData(singleProvinceData.push(each))
}
})
return data;
}).catch((err) => {
console.log(err);
})
}))
}, [])
useEffect(() => {
window.addEventListener("mousedown", handleClickOutside);
return () => {
window.removeEventListener("mousedown", handleClickOutside);
};
});
const handleClickOutside = event => {
const { current: wrap } = wrapperRef;
if (wrap && !wrap.contains(event.target)) {
setDisplay(false);
}
};
const updateProvince = inputProvince => {
setSearch(inputProvince);
setDisplay(false);
};
return (
<div ref={wrapperRef} className="flex-container flex-column pos-rel">
<input
id="auto"
onClick={() => setDisplay(!display)}
placeholder="Type to search"
value={search}
onChange={event => setSearch(event.target.value)}
/>
{display && (
<div className="autoContainer">
{ singleProvinceData
.filter( ({province}) => province.indexOf(search.toLowerCase()) > -1)
.map( (each,i) => {
return (
<div
onClick={() => updateProvince(each.province)}
className="singleProvinceData"
key={i}
tabIndex="0"
>
<span>{each.province}</span>
</div>
)
})}
</div>
)}
</div>
);
}
export default Test
When click on an input box, the console says "TypeError: singleProvinceData.filter is not a function"
enter image description here
I cannot find out what's wrong with my code

The issue is with the "singleProvinceData" state is not set correctly.
you cannot push data directly into the state.
useEffect(() => {
const promises = new Array(20).fill(fetch(province_dataBase_url)
.then((res) => {
return res.json().then((data) => {
const shallowSingleProvinceList = [];
const shallowSingleProvinceDataList = [];
const createSingleProvince = data.filter( (each) => {
if (false == (singleProvince.includes(each.province))) {
shallowSingleProvinceList.push(each.province)
shallowSingleProvinceDataList.push(each)
}
})
setSingleProvince(shallowSingleProvinceList)
setSingleProvinceData(shallowSingleProvinceDataList)
return data;
}).catch((err) => {
console.log(err);
})
}))
}, [])
You can show the data conditionally
{display && (
<div className="autoContainer">
{ singleProvinceData && singleProvinceData
.filter( ({province}) => province.indexOf(search.toLowerCase()) > -1)
.map( (each,i) => {
return (
<div
onClick={() => updateProvince(each.province)}
className="singleProvinceData"
key={i}
tabIndex="0"
>
<span>{each.province}</span>
</div>
)
})}
</div>
)}