Сделали useReducer для счетчика

src/App.jsx

@@ -1,44 +1,50 @@
-import { useMutation, QueryClientProvider, QueryClient } from '@tanstack/react-query'
-import PostAddForm from './components/PostAddForm'
+import { useState, useReducer } from 'react'
 
-/*
-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())
+function counterReducer(state, action) {
+    switch (action.type) {
+        case 'increment':
+            return state + 1
+        case 'decrement':
+            return state - 1
+        case 'reset':
+            return 0
+        case 'set_value':
+            return action.value
+        default:
+            return state
+    }
 }
-})
-*/
 
-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)}
-            }
-        }
-    })
+function Counter() {
+    const [count, dispatch] = useReducer(counterReducer,0);
+    
+    return (
+        <div>
+            <span>Счетчик: {count}</span>
+            <button onClick={()=> dispatch({type: 'increment'})}>+</button>
+            <button onClick={()=> dispatch({type: 'decrement'})}>-</button>
+            <button onClick={()=> dispatch({type: 'reset'})}>reset</button>
+            <button onClick={()=> dispatch({type: 'set_value', value: 5})}>set 5</button>
+        </div>
+    )
 }
 
 function App() {
+    const [tasks, setTasks] = useState([])
+    const [filter, setFilter] = useState('all')
+    const [sortBy,setSortBy] = useState('date')
+    
+    const addTask = newTask => {
+        setTasks([...tasks,newTask])
+    }
+    
+    
+    
 	return (
 		<>
 			{/* Добавьте тестовый контент для проверки */}
 			<h1>Hello, React!</h1>
-        <QueryClientProvider client={createQueryClient}>
-            <PostAddForm />
-        </QueryClientProvider>
-            
+            <Counter />
 		</>
 	)
 }

src/App.module.scss

@@ -0,0 +1,15 @@
+.container {
+/*    display: flex;
+    flex-direction: column;
+    flex-wrap: nowrap;*/
+    height: 500px;
+    overflow: auto;
+    border: 1px solid black;
+}
+.item {
+    font-size: 16pt;
+    border: 1px dotted gray;
+    /*margin: 5px 10px;
+    padding: 10px;*/
+    border-radius: 5px;
+}