Что то доделали. Надо сменить ветку

package-lock.json

@@ -8,7 +8,6 @@
       "name": "store-client",
       "version": "0.0.0",
       "dependencies": {
-        "@tanstack/react-query": "^5.100.14",
         "react": "^19.1.0",
         "react-dom": "^19.1.0"
       },
@@ -1305,32 +1304,6 @@
         "win32"
       ]
     },
-    "node_modules/@tanstack/query-core": {
-      "version": "5.100.14",
-      "resolved": "https://registry.npmjs.org/@tanstack/query-core/-/query-core-5.100.14.tgz",
-      "integrity": "sha512-5X41dGpxgeaHISCRW2oYwcSycZeULZzAunaudXT9ov1KOTj9xwt0CH6hbwqP1/z74ZWF7rYFnDpyYH07XFcZew==",
-      "license": "MIT",
-      "funding": {
-        "type": "github",
-        "url": "https://github.com/sponsors/tannerlinsley"
-      }
-    },
-    "node_modules/@tanstack/react-query": {
-      "version": "5.100.14",
-      "resolved": "https://registry.npmjs.org/@tanstack/react-query/-/react-query-5.100.14.tgz",
-      "integrity": "sha512-oOr6aRdSFEwWhzxEkD/9ZcItM3+LjBSkeVmadWKwUssAHTsqd/7bOjWrX4AbvEkoEhgAxzN0Xk6H/aYzXiYBAw==",
-      "license": "MIT",
-      "dependencies": {
-        "@tanstack/query-core": "5.100.14"
-      },
-      "funding": {
-        "type": "github",
-        "url": "https://github.com/sponsors/tannerlinsley"
-      },
-      "peerDependencies": {
-        "react": "^18 || ^19"
-      }
-    },
     "node_modules/@types/babel__core": {
       "version": "7.20.5",
       "resolved": "https://registry.npmjs.org/@types/babel__core/-/babel__core-7.20.5.tgz",

package.json

@@ -10,7 +10,6 @@
     "preview": "vite preview"
   },
   "dependencies": {
-    "@tanstack/react-query": "^5.100.14",
     "react": "^19.1.0",
     "react-dom": "^19.1.0"
   },

src/App.jsx

@@ -1,93 +1,96 @@
-import React, {useState, useEffect, useRef } from 'react'
-//import { useQuery } from '@tanstack/react-query'
+import React from 'react'
+import styles from './App.module.scss'
 
-function useWindowWidth() {
-    const [width,setWidth] = useState(window.innerWidth)
+class Clock extends React.Component {
+    constructor(props) {
+        super(props);
+        this.state = { date: new Date() };
+    }
+    componentDidMount() {
+        this.timerId = setInterval( () => this.tick(), 1000);
+    }
+    componentWillUnmount() {
+        clearInterval(this.timerId)
+    }
+    tick() {
+        this.setState({ date: new Date() })
+    }
+    render() {
+        return <div>{this.state.date.toLocaleTimeString()}</div>
+    }
+}
 
-    useEffect(() => {
-        const handleResize = () => setWidth(window.innerWidth);
-        window.addEventListener('resize',handleResize);
-        return () => window.removeEventListener('resize',handleResize);
+function Clock2() {
+    const [date, setDate] = React.useState(new Date());
+    
+    React.useEffect(()=>{
+        const timerId = setInterval(()=> setDate(new Date()),1000);
+        return () => clearInterval(timerId);
     },[])
     
-    return width
+    return <div>{date.toLocaleTimeString()}</div>
 }
 
-function useLocalStorage(key, initValue) {
-    const [value, setValue] = useState(()=>{
-        const stored = localStorage.getItem(key);
-        return stored !== null ? JSON.parse(stored) : initValue
-    })
+function MouseTracker() {
+    const [x,setX] = React.useState(0);
+    const [y,setY] = React.useState(0);
     
-    useEffect(() => {
-        localStorage.setItem(key, JSON.stringify(value))
-    },[key, value])
-    
-    return [value,setValue]
-}
-/*
-function useUserData(userId) {
-    return useQuery(
-        ['user',userId],
-        () => fetch(`/api/user/${userId}`).then(res => res.json()),
-        {refetchOnWindowFocus: false}
-    )
-}*/
-
-function useInput(initValue, validate) {
-    const [value, setValue] = useState(initValue);
-    const [error, setError] = useState(null);
-    
-    const onChange = e => {
-        const newValue = e.target.value
-        setValue(newValue)
-        if (validate) {
-            const validationResult = validate(newValue)
-            setError(validationResult)
-        }
+    const mouseMoveHandler = event => {
+        setX(event.clientX);
+        setY(event.clientY);
     }
     
-    return { value, error, onChange }
+    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 useInterval(callback, delay) {
-    const savedCallback = useRef()
+function DataFetcher() {
+    const [posts,setPosts] = React.useState([]);
+    const [users,setUsers] = React.useState([]);
     
-    useEffect(()=>{
-        savedCallback.current = callback
-    },[callback]);
+    const getPosts = async () => {
+        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));
         
-    useEffect(()=>{
-        if (delay == null) return
-        const id = setInterval(()=>{
-            savedCallback.current()
-        },delay);
-        return () => clearInterval(id);
-    },[delay])
+    }
+    
+    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() {
-    const width = useWindowWidth();
-    const [theme, setTheme] = useLocalStorage('theme','light');
-    
-    const username = useInput(
-        '',
-        value => value.length < 3 ? 'минимум 3 символа' : null
-    )
+    const [tracker,setTracker] = React.useState(false);
+    const [dataFetcher,setDataFetcher] = React.useState(false);
     
 	return (
 		<>
-			<h1>Hello, React!{width}</h1>
-            <button onClick={()=>{
-                setTheme(theme === 'light' ? 'dark' : 'light')
-            }}>
-                Сменить тему
-            </button>
-            <p><input type="text" 
-                value={username.value} 
-                onChange={username.onChange} />
-                { username.error ? username.error : '' }
-            </p>
+			<h1>Hello, React!</h1>
+            <Clock />
+            <Clock2 />
+            <button onClick={() => setTracker(!tracker)}>Показать/Скрыть трекер</button>
+            { tracker && <MouseTracker /> }
+            <button onClick={() => setDataFetcher(!dataFetcher)}>Показать/Скрыть посты</button>
+            { dataFetcher && <DataFetcher /> }
 		</>
 	)
 }

src/App.module.scss

@@ -0,0 +1,11 @@
+.container {
+    width: 300px;
+    height: 200px;
+    border: 2px dashed grey;
+    margin: 10px;
+    text-align: center;
+    p {
+        margin-top: 20%;
+    }
+}
+