Сделали React.memo и React.useMemo

package-lock.json

@@ -9,9 +9,7 @@
       "version": "0.0.0",
       "dependencies": {
         "react": "^19.1.0",
-        "react-dom": "^19.1.0",
-        "react-error-boundary": "^6.1.2",
-        "react-router-dom": "^7.17.0"
+        "react-dom": "^19.1.0"
       },
       "devDependencies": {
         "@eslint/js": "^9.25.0",
@@ -1602,19 +1600,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/cookie": {
-      "version": "1.1.1",
-      "resolved": "https://registry.npmjs.org/cookie/-/cookie-1.1.1.tgz",
-      "integrity": "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=18"
-      },
-      "funding": {
-        "type": "opencollective",
-        "url": "https://opencollective.com/express"
-      }
-    },
     "node_modules/cross-spawn": {
       "version": "7.0.6",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",
@@ -2476,15 +2461,6 @@
         "react": "^19.1.0"
       }
     },
-    "node_modules/react-error-boundary": {
-      "version": "6.1.2",
-      "resolved": "https://registry.npmjs.org/react-error-boundary/-/react-error-boundary-6.1.2.tgz",
-      "integrity": "sha512-3DpCr5HVdZ0caUjYE/kIHBEJN0mNP3ZCgf16c48uJ5TbWjorKVp+YG8W3XqlJ7vJAVNw6wNIImyPXmFydwmyng==",
-      "license": "MIT",
-      "peerDependencies": {
-        "react": "^18.0.0 || ^19.0.0"
-      }
-    },
     "node_modules/react-refresh": {
       "version": "0.17.0",
       "resolved": "https://registry.npmjs.org/react-refresh/-/react-refresh-0.17.0.tgz",
@@ -2495,44 +2471,6 @@
         "node": ">=0.10.0"
       }
     },
-    "node_modules/react-router": {
-      "version": "7.17.0",
-      "resolved": "https://registry.npmjs.org/react-router/-/react-router-7.17.0.tgz",
-      "integrity": "sha512-FDELK7rTMlCHO5+reyXsPlmfr7N1F91lPHsWYfMEGQm/KQ+F4JFM8jGoeQDmDvdTs93Fw9aSilH+uKRb4/jXvQ==",
-      "license": "MIT",
-      "dependencies": {
-        "cookie": "^1.0.1",
-        "set-cookie-parser": "^2.6.0"
-      },
-      "engines": {
-        "node": ">=20.0.0"
-      },
-      "peerDependencies": {
-        "react": ">=18",
-        "react-dom": ">=18"
-      },
-      "peerDependenciesMeta": {
-        "react-dom": {
-          "optional": true
-        }
-      }
-    },
-    "node_modules/react-router-dom": {
-      "version": "7.17.0",
-      "resolved": "https://registry.npmjs.org/react-router-dom/-/react-router-dom-7.17.0.tgz",
-      "integrity": "sha512-fyU2yjGups/hE6Xz0I5ZYbVL8Gx29eCjgpHaRaTaVU+OOAdfRX05KsvyRm0GO8YQwOkhpU3MurW1jyMUJn+zSw==",
-      "license": "MIT",
-      "dependencies": {
-        "react-router": "7.17.0"
-      },
-      "engines": {
-        "node": ">=20.0.0"
-      },
-      "peerDependencies": {
-        "react": ">=18",
-        "react-dom": ">=18"
-      }
-    },
     "node_modules/resolve-from": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/resolve-from/-/resolve-from-4.0.0.tgz",
@@ -2606,12 +2544,6 @@
         "semver": "bin/semver.js"
       }
     },
-    "node_modules/set-cookie-parser": {
-      "version": "2.7.2",
-      "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-2.7.2.tgz",
-      "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw==",
-      "license": "MIT"
-    },
     "node_modules/shebang-command": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/shebang-command/-/shebang-command-2.0.0.tgz",

package.json

@@ -4,16 +4,14 @@
   "version": "0.0.0",
   "type": "module",
   "scripts": {
-    "dev": "vite",
+    "dev": "vite", 
     "build": "vite build",
     "lint": "eslint .",
     "preview": "vite preview"
   },
   "dependencies": {
     "react": "^19.1.0",
-    "react-dom": "^19.1.0",
-    "react-error-boundary": "^6.1.2",
-    "react-router-dom": "^7.17.0"
+    "react-dom": "^19.1.0"
   },
   "devDependencies": {
     "@eslint/js": "^9.25.0",

src/App.jsx

@@ -1,26 +1,60 @@
-import { Suspense, lazy } from 'react'
-import { ErrorBoundary } from 'react-error-boundary'
+import { memo, useState, useMemo } from 'react'
 
-const LazyComponent = lazy(() => import('./MyComponent'))
+function memoize(fn) {
+    const cache = new Map();
+    return function(...args) {
+        const key = JSON.stringify(args);
+        if (cache.has(key)) {
+            return cache.get(key);
+        }
+        const result = fn.apply(this, args);
+        cache.set(key,result);
+        return result;
+    }
+}
 
-function ErrorFallBack({error, resetErrorBoundary }) {
+function fibonachi(n, memo={}) {
+    if (n in memo) {console.log(n);return memo[n];}
+    if (n <= 1) return 1;
+    memo[n] = fibonachi(n-1, memo) + fibonachi(n - 2, memo);
+    return memo[n];
+}
+
+const MyComponent = ({ value }) => {
+    console.log('Rendring');
+    return <div>{value}</div>
+}
+
+const MemoizedComponent = memo(MyComponent);
+
+const Child = memo(({ children }) => {
+    console.log('Child component rendred');
+    return <div>{children}</div>;
+});
+
+const Parent = () => {
+    const [count,setCount] = useState(0);
+    const [text, setText] = useState('');
+    
+    const stableChild = useMemo(() => <span>Memo text</span>,[]);
+    
     return (
-        <div>
-            <h2>Что то сломалось</h2>
-            <button onClick={resetErrorBoundary}></button>
-        </div>
+        <>
+            <Child>
+                {stableChild}
+            </Child>
+            <input type="text" onChange={(e) => setText(e.target.value)} value={text} />
+            <button onClick={() => setCount(count + 1)}>Increment {count}</button>
+        </>
     )
 }
 
 function App() {
 	return (
 		<>
-			<ErrorBoundary FallBackComponent={ErrorFallBack}>
-                <Suspense fallback={<div>Загрузка ...</div>}>
-			        <LazyComponent />
-                </Suspense>
-            </ErrorBoundary>
-		</>
+			<h1>Hello, React!</h1>
+            <Parent />
+        </>
 	)
 }
 

src/main.jsx

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