i dont know

src/App.jsx

@@ -1,108 +1,44 @@
-import React from 'react'
+import { useMutation, QueryClientProvider, QueryClient } from '@tanstack/react-query'
+import PostAddForm from './components/PostAddForm'
 
-class MyComponent extends React.Component {
-    constructor(props) {
-        super(props);
-        this.state = { data: null };
-        this.handleClick = this.handleClick.bind(this);
+/*
+const mutation = useMutation({
+    mutationFn: newUser => {
+        fetch('https://jsonplaceholder.typicode.com/users', {
+            method: 'GET',
+            headers: {'Content-type':'application/json'},
+            body: JSON.stringify(newUser),
+        }).then(res => res.json())
     }
-    
-    render() {
-        return (
-            <div>
-            {this.state.data ? (
-                    <div>Данные: {this.state.data}</div>
-                ) : (
-                    <div>Загрузка...</div>
-                )}
-                <button onClick={this.handleClick}>Обновить</button>
-            </div>
-        )
-    }
-    
-    componentDidMount() {
-        fetch('https://api.example.com/data')
-        .then(responce => responce.json())
-        .then(json => this.setState({data: json}));
-        
-        this.timerId = setInterval(()=> console.log('Tick'), 1000);
-    }
-    
-    componentWillUnmout() {
-        clearInterval(this.timerId);
-    }
-    
-    handleClick() {
-        this.setState({data: 'Данные'})
-    }
-}
+})
+*/
 
-class MyComponent2 extends React.Component {
-    controller = new AbortController()
-
-    componentDidMount() {
-        fetch('https://api.example.com/data',{ singnal: this.controller.signal })
-        .then(responce => responce.json())
-        .then(json => this.setState({data: json}))
-        .catch(error => {
-            if(error.name == 'AbortError') {
-                console.log('Aborted');
-            } else {
-                console.log('Other error',error);
+const createQueryClient = () => {
+    new QueryClient({
+        defaultOptions: {
+            queries: {
+                staleTime: 5 * 60*1000,
+                retry: 1,
+                gcTime: 10*60*1000,
+                refetchOnWindowFocus: false,
+            },
+            mutations: {
+                retry:0,
+                onError: error => {console.error('Mutation error:',error.message)}
             }
-        });
-    }
-
-    componentWillUnmount() {
-        this.controller.abort()
-    }
-}
-class MyComponent3 extends React.Component {
-    componentDidMount() {
-        this.loadData();
-    }
-    
-    async loadData() {
-        try {
-            const response = await fetch('https://api.example.com/data');
-            const data = await response.json();
-            this.setSate({ data });
-        } catch {
-            console.log('error');
         }
-    }
-}
-
-class Timer extends React.Component {
-    constructor(props) {
-        super(props);
-        this.state = { seconds: 0 }
-    }
-    
-    componentDidMount() {
-        console.log('Timer mounted');
-        this.interval = setInterval(()=>{
-            this.setState(prevState => ({seconds: prevState.seconds + 1}))
-        },1000);
-    }
-    
-    componentWillUnmount() {
-        console.log('Timer unmount');
-        clearInterval(this.interval);
-    }
-    render() {
-        return <h2>Прошло секунд: {this.state.seconds}</h2>
-    }
+    })
 }
 
 function App() {
-    const [show,setShow] = React.useState(true);
-    
 	return (
 		<>
-			<h1>Таймер с классом</h1>
-            <button onClick={()=>setShow(prev => !prev)}>{show ? 'Скрыть' : 'Показать'} таймер</button>
-            {show && <Timer />}
+			{/* Добавьте тестовый контент для проверки */}
+			<h1>Hello, React!</h1>
+        <QueryClientProvider client={createQueryClient}>
+            <PostAddForm />
+        </QueryClientProvider>
+            
 		</>
 	)
 }

src/main.jsx

@@ -4,5 +4,7 @@ import { createRoot } from 'react-dom/client'
 import App from './App.jsx'
 
 createRoot(document.getElementById('root')).render(
+	<StrictMode>
 		<App />
+	</StrictMode>
 )