Что то доделали. Надо сменить ветку

src/App.jsx

@@ -1,78 +1,96 @@
-import { useState, createContext, useContext } from 'react'
+import React from 'react'
 import styles from './App.module.scss'
 
-const UserContext = createContext('')
+class Clock extends React.Component {
-
+    constructor(props) {
-function UserProvider({ children }) {
+        super(props);
-    const [name,setName] = useState('');
+        this.state = { date: new Date() };
-    
+    }
-    const toggleName = (newName) => {
+    componentDidMount() {
-        setName(newName);
+        this.timerId = setInterval( () => this.tick(), 1000);
+    }
+    componentWillUnmount() {
+        clearInterval(this.timerId)
+    }
+    tick() {
+        this.setState({ date: new Date() })
+    }
+    render() {
+        return <div>{this.state.date.toLocaleTimeString()}</div>
     }
-    
-    return (
-        <UserContext.Provider value={{name, toggleName}}>
-            {children}
-        </UserContext.Provider>
-    )
 }
 
-function Form() {
+function Clock2() {
-    const {name, toggleName} = useContext(UserContext)
+    const [date, setDate] = React.useState(new Date());
-    const [newName,setNewName] = useState('');
-    const handleSubmit = (event) => {
-        event.preventDefault();
-        toggleName(event.target[0].value)
-    }
-    const handlerChange = (event) => {
-        setNewName(event.target.value);
-    }
-    return (
-        <form onSubmit={handleSubmit}>
-        <input type='text' value={newName} onChange={handlerChange} />
-        <button type='submit'>Войти</button>
-        </form>
-    )
-}
-
-function ExitButton() {
-    const {name, toggleName} = useContext(UserContext)
     
-    return (
+    React.useEffect(()=>{
-        <button onClick={() => toggleName('')}>Выход</button>
+        const timerId = setInterval(()=> setDate(new Date()),1000);
-    )
+        return () => clearInterval(timerId);
+    },[])
+    
+    return <div>{date.toLocaleTimeString()}</div>
 }
 
-function Toolbar() {
+function MouseTracker() {
-    const {name, toggleName} = useContext(UserContext)
+    const [x,setX] = React.useState(0);
-    return(
+    const [y,setY] = React.useState(0);
-        <div className={styles.container}>
+    
-            <h3>Панель пользователя</h3>
+    const mouseMoveHandler = event => {
-            {name && `Привет ${name}`}
+        setX(event.clientX);
-            {name ? <ExitButton /> : <Form /> }
+        setY(event.clientY);
-            
+    }
+    
+    React.useEffect(()=>{
+        document.addEventListener('mousemove', mouseMoveHandler);
+        return () => {
+            document.removeEventListener('mousemove',mouseMoveHandler);
+        }
+    },[]);
+    
+    return <div className={styles.container}>
+        <p>Координаты мыши:<br /> X:<b>{x}</b>, Y:<b>{y}</b></p>
         </div>
-    )
 }
 
-function Page() {
+function DataFetcher() {
-    return (
+    const [posts,setPosts] = React.useState([]);
-        <div>
+    const [users,setUsers] = React.useState([]);
-            <h1 style={{textAlign: 'center'}}>Главная страница</h1>
+    
-            <Toolbar />
+    const getPosts = async () => {
-        </div>
+        const response = await fetch('https://jsonplaceholder.typicode.com/posts');
-    )
+        const data = await response.json();
+        setUsers(data.reduce((acc, value) => {
+            if (!(value.userId in acc))
+                return [...acc,value.userId]
+            return acc
+        }))
+        console.log(users);
+        setPosts(data.slice(1,10));
+        
+    }
+    
+    React.useEffect(() => {
+        console.log("Компонент создан");
+        getPosts();
+        return () => {console.log("Компонент удален");setPosts([])};
+    },[])
+    
+    return <div><ol>{posts.map(post => <li id={post.id}>{post.title}</li>)}</ol></div>
 }
 
-function App() {    
+function App() {
+    const [tracker,setTracker] = React.useState(false);
+    const [dataFetcher,setDataFetcher] = React.useState(false);
     
 	return (
 		<>
-			{/* Добавьте тестовый контент для проверки */}
 			<h1>Hello, React!</h1>
-        <UserProvider>
+            <Clock />
-            <Page />
+            <Clock2 />
-        </UserProvider>
+            <button onClick={() => setTracker(!tracker)}>Показать/Скрыть трекер</button>
+            { tracker && <MouseTracker /> }
+            <button onClick={() => setDataFetcher(!dataFetcher)}>Показать/Скрыть посты</button>
+            { dataFetcher && <DataFetcher /> }
 		</>
 	)
 }

src/App.module.scss

@@ -1,13 +1,11 @@
 .container {
-    height: 500px;
+    width: 300px;
-    border: 1px solid black;
+    height: 200px;
-    border-radius: 10px;
+    border: 2px dashed grey;
-    background-color: lightblue;
+    margin: 10px;
+    text-align: center;
+    p {
+        margin-top: 20%;
+    }
 }
-.item {
+
-    font-size: 16pt;
-    border: 1px dotted gray;
-    /*margin: 5px 10px;
-    padding: 10px;*/
-    border-radius: 5px;
-}