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CodeWorlds

use - universal hook for handling Promise and Context

The

use
hook is an experimental React feature that allows you to "use" resources such as Promises or Context. It is the first hook that can be called conditionally and in loops, opening new possibilities in writing components.

use Basics

1. Reading Promise with use

1import { use, Suspense } from 'react';
2
3// Function returning a Promise
4function fetchUser(id) {
5  return fetch(`/api/users/${id}`).then(res => res.json());
6}
7
8// Component using use with Promise
9function UserProfile({ userPromise }) {
10  // use automatically "unwraps" the Promise
11  const user = use(userPromise);
12
13  return (
14    <div style={{
15      padding: '20px',
16      border: '1px solid #ddd',
17      borderRadius: '8px'
18    }}>
19      <h2>{user.name}</h2>
20      <p>Email: {user.email}</p>
21      <p>Joined: {new Date(user.joinedDate).toLocaleDateString('en-US')}</p>
22    </div>
23  );
24}
25
26// Parent component
27function UserDashboard({ userId }) {
28  // Create Promise once to avoid multiple requests
29  const userPromise = fetchUser(userId);
30
31  return (
32    <div>
33      <h1>User Dashboard</h1>
34      <Suspense fallback={<div>Loading user data...</div>}>
35        <UserProfile userPromise={userPromise} />
36      </Suspense>
37    </div>
38  );
39}

2. Using use with Context

1import { use, createContext, useState } from 'react';
2
3// Creating Context
4const ThemeContext = createContext(null);
5const UserContext = createContext(null);
6
7// Component using use with Context
8function Header() {
9  // use can be used conditionally!
10  const theme = use(ThemeContext);
11  const user = use(UserContext);
12
13  return (
14    <header style={{
15      backgroundColor: theme === 'dark' ? '#333' : '#f8f9fa',
16      color: theme === 'dark' ? '#fff' : '#333',
17      padding: '20px'
18    }}>
19      <h1>Welcome, {user.name}!</h1>
20      <p>Current theme: {theme}</p>
21    </header>
22  );
23}
24
25// Ability to use conditionally
26function ConditionalComponent({ showUserInfo }) {
27  const theme = use(ThemeContext);
28
29  // use can be used conditionally - this is impossible with other hooks!
30  if (showUserInfo) {
31    const user = use(UserContext);
32    return <div>User: {user.name}</div>;
33  }
34
35  return <div>Theme: {theme}</div>;
36}
37
38// App with providers
39function App() {
40  const [theme, setTheme] = useState('light');
41  const [user] = useState({ name: 'John Smith', id: 1 });
42
43  return (
44    <ThemeContext.Provider value={theme}>
45      <UserContext.Provider value={user}>
46        <div>
47          <Header />
48          <ConditionalComponent showUserInfo={true} />
49          <button onClick={() => setTheme(t => t === 'light' ? 'dark' : 'light')}>
50            Toggle theme
51          </button>
52        </div>
53      </UserContext.Provider>
54    </ThemeContext.Provider>
55  );
56}

3. use in loops

1import { use, Suspense } from 'react';
2
3// Function creating a Promise for each post
4function fetchPost(id) {
5  return fetch(`/api/posts/${id}`).then(res => res.json());
6}
7
8// Component displaying multiple posts
9function PostList({ postIds }) {
10  const posts = postIds.map(id => {
11    // use can be used in loops!
12    const postPromise = fetchPost(id);
13    // eslint-disable-next-line react-hooks/rules-of-hooks
14    const post = use(postPromise);
15    return post;
16  });
17
18  return (
19    <div>
20      {posts.map(post => (
21        <article
22          key={post.id}
23          style={{
24            marginBottom: '20px',
25            padding: '15px',
26            backgroundColor: '#f8f9fa',
27            borderRadius: '8px'
28          }}
29        >
30          <h3>{post.title}</h3>
31          <p>{post.content}</p>
32          <small>Author: {post.author}</small>
33        </article>
34      ))}
35    </div>
36  );
37}
38
39// Wrapper with Suspense
40function BlogSection() {
41  const postIds = [1, 2, 3, 4, 5];
42
43  return (
44    <section>
45      <h2>Latest Posts</h2>
46      <Suspense fallback={<PostListSkeleton count={5} />}>
47        <PostList postIds={postIds} />
48      </Suspense>
49    </section>
50  );
51}
52
53function PostListSkeleton({ count }) {
54  return (
55    <div>
56      {Array.from({ length: count }).map((_, i) => (
57        <div
58          key={i}
59          style={{
60            marginBottom: '20px',
61            padding: '15px',
62            backgroundColor: '#e9ecef',
63            borderRadius: '8px',
64            height: '100px'
65          }}
66        />
67      ))}
68    </div>
69  );
70}

Advanced patterns with use

1. Cache for Promises

1import { use, Suspense, useState } from 'react';
2
3// Simple cache for Promises
4const promiseCache = new Map();
5
6function getCachedPromise(key, promiseFactory) {
7  if (!promiseCache.has(key)) {
8    promiseCache.set(key, promiseFactory());
9  }
10  return promiseCache.get(key);
11}
12
13// API functions
14function fetchUserData(userId) {
15  const cached = getCachedPromise(
16    `user-${userId}`,
17    () => fetch(`/api/users/${userId}`).then(res => res.json())
18  );
19  return cached;
20}
21
22function fetchUserPosts(userId) {
23  const cached = getCachedPromise(
24    `posts-${userId}`,
25    () => fetch(`/api/users/${userId}/posts`).then(res => res.json())
26  );
27  return cached;
28}
29
30// Components
31function UserInfo({ userId }) {
32  const userPromise = fetchUserData(userId);
33  const user = use(userPromise);
34
35  return (
36    <div style={{
37      padding: '20px',
38      backgroundColor: '#f8f9fa',
39      borderRadius: '8px',
40      marginBottom: '20px'
41    }}>
42      <h2>{user.name}</h2>
43      <p>{user.email}</p>
44      <p>{user.location}</p>
45      <p>Joined: {new Date(user.joinedDate).toLocaleDateString('en-US')}</p>
46    </div>
47  );
48}
49
50function UserPosts({ userId }) {
51  const postsPromise = fetchUserPosts(userId);
52  const posts = use(postsPromise);
53
54  return (
55    <div>
56      <h3>User posts ({posts.length})</h3>
57      {posts.map(post => (
58        <article
59          key={post.id}
60          style={{
61            marginBottom: '15px',
62            padding: '15px',
63            border: '1px solid #e9ecef',
64            borderRadius: '6px'
65          }}
66        >
67          <h4>{post.title}</h4>
68          <p>{post.excerpt}</p>
69          <small>{new Date(post.date).toLocaleDateString('en-US')}</small>
70        </article>
71      ))}
72    </div>
73  );
74}
75
76function UserProfilePage() {
77  const [userId, setUserId] = useState(1);
78
79  return (
80    <div style={{ maxWidth: '800px', margin: '0 auto', padding: '20px' }}>
81      <div style={{ marginBottom: '20px' }}>
82        <button onClick={() => setUserId(1)} disabled={userId === 1}>
83          User 1
84        </button>
85        <button onClick={() => setUserId(2)} disabled={userId === 2}>
86          User 2
87        </button>
88        <button onClick={() => promiseCache.clear()}>
89          Clear cache
90        </button>
91      </div>
92
93      <Suspense fallback={<div>Loading profile...</div>}>
94        <UserInfo userId={userId} />
95      </Suspense>
96
97      <Suspense fallback={<div>Loading posts...</div>}>
98        <UserPosts userId={userId} />
99      </Suspense>
100    </div>
101  );
102}

2. Parallel data loading

1import { use, Suspense } from 'react';
2
3// API functions
4async function fetchDashboardData() {
5  const [stats, activities, notifications] = await Promise.all([
6    fetch('/api/stats').then(res => res.json()),
7    fetch('/api/activities').then(res => res.json()),
8    fetch('/api/notifications').then(res => res.json())
9  ]);
10
11  return { stats, activities, notifications };
12}
13
14// Dashboard component
15function Dashboard({ dataPromise }) {
16  const { stats, activities, notifications } = use(dataPromise);
17
18  return (
19    <div style={{
20      display: 'grid',
21      gridTemplateColumns: 'repeat(auto-fit, minmax(300px, 1fr))',
22      gap: '20px',
23      padding: '20px'
24    }}>
25      <StatsCard stats={stats} />
26      <ActivitiesCard activities={activities} />
27      <NotificationsCard notifications={notifications} />
28    </div>
29  );
30}
31
32function StatsCard({ stats }) {
33  return (
34    <div style={{
35      padding: '20px',
36      backgroundColor: '#f8f9fa',
37      borderRadius: '8px',
38      boxShadow: '0 2px 4px rgba(0,0,0,0.1)'
39    }}>
40      <h3>Statistics</h3>
41      <div style={{ display: 'grid', gap: '10px' }}>
42        <div>
43          <strong>Users:</strong> {stats.users.toLocaleString('en-US')}
44        </div>
45        <div>
46          <strong>Revenue:</strong> {stats.revenue.toLocaleString('en-US', {
47            style: 'currency',
48            currency: 'USD'
49          })}
50        </div>
51        <div>
52          <strong>Growth:</strong>
53          <span style={{ color: stats.growth > 0 ? '#28a745' : '#dc3545' }}>
54            {stats.growth > 0 ? '+' : ''}{stats.growth}%
55          </span>
56        </div>
57      </div>
58    </div>
59  );
60}
61
62function ActivitiesCard({ activities }) {
63  return (
64    <div style={{
65      padding: '20px',
66      backgroundColor: '#f8f9fa',
67      borderRadius: '8px',
68      boxShadow: '0 2px 4px rgba(0,0,0,0.1)'
69    }}>
70      <h3>Recent Activities</h3>
71      <ul style={{ listStyle: 'none', padding: 0 }}>
72        {activities.slice(0, 5).map(activity => (
73          <li
74            key={activity.id}
75            style={{
76              padding: '8px 0',
77              borderBottom: '1px solid #e9ecef'
78            }}
79          >
80            <div style={{ fontWeight: '500' }}>{activity.user}</div>
81            <div style={{ fontSize: '14px', color: '#6c757d' }}>
82              {activity.action}
83            </div>
84            <small style={{ color: '#6c757d' }}>
85              {new Date(activity.timestamp).toLocaleString('en-US')}
86            </small>
87          </li>
88        ))}
89      </ul>
90    </div>
91  );
92}
93
94function NotificationsCard({ notifications }) {
95  const unreadCount = notifications.filter(n => !n.read).length;
96
97  return (
98    <div style={{
99      padding: '20px',
100      backgroundColor: '#f8f9fa',
101      borderRadius: '8px',
102      boxShadow: '0 2px 4px rgba(0,0,0,0.1)'
103    }}>
104      <h3>
105        Notifications
106        {unreadCount > 0 && (
107          <span style={{
108            marginLeft: '10px',
109            padding: '2px 8px',
110            backgroundColor: '#dc3545',
111            color: 'white',
112            borderRadius: '12px',
113            fontSize: '14px'
114          }}>
115            {unreadCount}
116          </span>
117        )}
118      </h3>
119      <div style={{ maxHeight: '200px', overflowY: 'auto' }}>
120        {notifications.map(notification => (
121          <div
122            key={notification.id}
123            style={{
124              padding: '10px',
125              marginBottom: '8px',
126              backgroundColor: notification.read ? 'transparent' : '#e3f2fd',
127              borderRadius: '4px',
128              fontSize: '14px'
129            }}
130          >
131            <strong>{notification.title}</strong>
132            <p style={{ margin: '4px 0' }}>{notification.message}</p>
133          </div>
134        ))}
135      </div>
136    </div>
137  );
138}
139
140// Main component
141function DashboardApp() {
142  const dataPromise = fetchDashboardData();
143
144  return (
145    <div>
146      <h1 style={{ padding: '20px' }}>Admin Panel</h1>
147      <Suspense fallback={<DashboardSkeleton />}>
148        <Dashboard dataPromise={dataPromise} />
149      </Suspense>
150    </div>
151  );
152}
153
154function DashboardSkeleton() {
155  return (
156    <div style={{
157      display: 'grid',
158      gridTemplateColumns: 'repeat(auto-fit, minmax(300px, 1fr))',
159      gap: '20px',
160      padding: '20px'
161    }}>
162      {[1, 2, 3].map(i => (
163        <div
164          key={i}
165          style={{
166            height: '250px',
167            backgroundColor: '#e9ecef',
168            borderRadius: '8px',
169            animation: 'pulse 1.5s ease-in-out infinite'
170          }}
171        />
172      ))}
173    </div>
174  );
175}

3. Error boundaries with use

1import { use, Suspense, Component } from 'react';
2
3// Error Boundary
4class ErrorBoundary extends Component {
5  constructor(props) {
6    super(props);
7    this.state = { hasError: false, error: null };
8  }
9
10  static getDerivedStateFromError(error) {
11    return { hasError: true, error };
12  }
13
14  componentDidCatch(error, errorInfo) {
15    console.error('Error caught by boundary:', error, errorInfo);
16  }
17
18  render() {
19    if (this.state.hasError) {
20      return (
21        <div style={{
22          padding: '20px',
23          backgroundColor: '#f8d7da',
24          border: '1px solid #f5c6cb',
25          borderRadius: '8px',
26          color: '#721c24'
27        }}>
28          <h3>Something went wrong</h3>
29          <p>{this.state.error?.message || 'Unknown error'}</p>
30          <button
31            onClick={() => this.setState({ hasError: false, error: null })}
32            style={{
33              marginTop: '10px',
34              padding: '8px 16px',
35              backgroundColor: '#721c24',
36              color: 'white',
37              border: 'none',
38              borderRadius: '4px',
39              cursor: 'pointer'
40            }}
41          >
42            Try again
43          </button>
44        </div>
45      );
46    }
47
48    return this.props.children;
49  }
50}
51
52// API function that may return an error
53function fetchDataWithError(shouldFail = false) {
54  return new Promise((resolve, reject) => {
55    setTimeout(() => {
56      if (shouldFail) {
57        reject(new Error('Error fetching data from server'));
58      } else {
59        resolve({
60          message: 'Data loaded successfully!',
61          timestamp: new Date().toISOString()
62        });
63      }
64    }, 1000);
65  });
66}
67
68// Component using use
69function DataDisplay({ dataPromise }) {
70  const data = use(dataPromise);
71
72  return (
73    <div style={{
74      padding: '20px',
75      backgroundColor: '#d4edda',
76      border: '1px solid #c3e6cb',
77      borderRadius: '8px',
78      color: '#155724'
79    }}>
80      <h3>Success!</h3>
81      <p>{data.message}</p>
82      <small>Loaded: {new Date(data.timestamp).toLocaleString('en-US')}</small>
83    </div>
84  );
85}
86
87// Main component
88function ErrorHandlingDemo() {
89  const [shouldFail, setShouldFail] = useState(false);
90  const [key, setKey] = useState(0);
91
92  const dataPromise = fetchDataWithError(shouldFail);
93
94  return (
95    <div style={{ maxWidth: '600px', margin: '0 auto', padding: '20px' }}>
96      <h2>Error handling with use</h2>
97
98      <div style={{ marginBottom: '20px' }}>
99        <label>
100          <input
101            type="checkbox"
102            checked={shouldFail}
103            onChange={(e) => setShouldFail(e.target.checked)}
104          />
105          Simulate error
106        </label>
107        <button
108          onClick={() => setKey(k => k + 1)}
109          style={{ marginLeft: '20px' }}
110        >
111          Refresh
112        </button>
113      </div>
114
115      <ErrorBoundary key={key}>
116        <Suspense fallback={
117          <div style={{
118            padding: '20px',
119            backgroundColor: '#cfe2ff',
120            border: '1px solid #b6d4fe',
121            borderRadius: '8px',
122            color: '#084298'
123          }}>
124            Loading data...
125          </div>
126        }>
127          <DataDisplay dataPromise={dataPromise} />
128        </Suspense>
129      </ErrorBoundary>
130    </div>
131  );
132}

Practical applications of use

1. Routing system with lazy loading

1import { use, Suspense, lazy, useState } from 'react';
2
3// Simulation of a routing system
4const routes = {
5  '/': lazy(() => import('./pages/Home')),
6  '/about': lazy(() => import('./pages/About')),
7  '/contact': lazy(() => import('./pages/Contact')),
8  '/profile': lazy(() => import('./pages/Profile'))
9};
10
11// Context for routing
12const RouteContext = createContext(null);
13
14// Navigation hook
15function useNavigation() {
16  const { navigate } = use(RouteContext);
17  return navigate;
18}
19
20// Page component
21function Page({ path }) {
22  const Component = routes[path] || routes['/'];
23
24  return (
25    <Suspense fallback={<PageLoader />}>
26      <Component />
27    </Suspense>
28  );
29}
30
31function PageLoader() {
32  return (
33    <div style={{
34      display: 'flex',
35      justifyContent: 'center',
36      alignItems: 'center',
37      minHeight: '400px'
38    }}>
39      <div style={{ textAlign: 'center' }}>
40        <div style={{
41          width: '50px',
42          height: '50px',
43          border: '3px solid #f3f3f3',
44          borderTop: '3px solid #007bff',
45          borderRadius: '50%',
46          animation: 'spin 1s linear infinite',
47          margin: '0 auto 20px'
48        }} />
49        <p>Loading page...</p>
50      </div>
51    </div>
52  );
53}
54
55// Main application
56function RouterApp() {
57  const [currentPath, setCurrentPath] = useState('/');
58
59  const navigate = (path) => {
60    setCurrentPath(path);
61    window.history.pushState({}, '', path);
62  };
63
64  return (
65    <RouteContext.Provider value={{ navigate, currentPath }}>
66      <div style={{ minHeight: '100vh', display: 'flex', flexDirection: 'column' }}>
67        <Navigation />
68        <main style={{ flex: 1, padding: '20px' }}>
69          <Page path={currentPath} />
70        </main>
71      </div>
72    </RouteContext.Provider>
73  );
74}
75
76function Navigation() {
77  const navigate = useNavigation();
78  const { currentPath } = use(RouteContext);
79
80  const links = [
81    { path: '/', label: 'Home' },
82    { path: '/about', label: 'About' },
83    { path: '/contact', label: 'Contact' },
84    { path: '/profile', label: 'Profile' }
85  ];
86
87  return (
88    <nav style={{
89      backgroundColor: '#333',
90      padding: '10px 20px'
91    }}>
92      {links.map(link => (
93        <button
94          key={link.path}
95          onClick={() => navigate(link.path)}
96          style={{
97            marginRight: '10px',
98            padding: '8px 16px',
99            backgroundColor: currentPath === link.path ? '#007bff' : 'transparent',
100            color: 'white',
101            border: 'none',
102            borderRadius: '4px',
103            cursor: 'pointer'
104          }}
105        >
106          {link.label}
107        </button>
108      ))}
109    </nav>
110  );
111}

2. Dynamic forms with validation

1import { use, createContext, useState } from 'react';
2
3// Context for the form
4const FormContext = createContext(null);
5
6// Hook for form management
7function useFormField(name) {
8  const form = use(FormContext);
9
10  return {
11    value: form.values[name] || '',
12    error: form.errors[name],
13    onChange: (e) => form.setValue(name, e.target.value),
14    onBlur: () => form.validateField(name)
15  };
16}
17
18// Form field component
19function FormField({ name, label, type = 'text', validate }) {
20  const field = useFormField(name);
21  const form = use(FormContext);
22
23  // Register validator
24  if (validate && !form.validators[name]) {
25    form.registerValidator(name, validate);
26  }
27
28  return (
29    <div style={{ marginBottom: '15px' }}>
30      <label style={{ display: 'block', marginBottom: '5px', fontWeight: 'bold' }}>
31        {label}
32      </label>
33      <input
34        type={type}
35        value={field.value}
36        onChange={field.onChange}
37        onBlur={field.onBlur}
38        style={{
39          width: '100%',
40          padding: '8px',
41          border: `1px solid ${field.error ? '#dc3545' : '#ddd'}`,
42          borderRadius: '4px'
43        }}
44      />
45      {field.error && (
46        <div style={{ color: '#dc3545', fontSize: '14px', marginTop: '5px' }}>
47          {field.error}
48        </div>
49      )}
50    </div>
51  );
52}
53
54// Form provider
55function FormProvider({ children, onSubmit }) {
56  const [values, setValues] = useState({});
57  const [errors, setErrors] = useState({});
58  const [validators] = useState({});
59
60  const setValue = (name, value) => {
61    setValues(prev => ({ ...prev, [name]: value }));
62    // Clear error on value change
63    setErrors(prev => ({ ...prev, [name]: '' }));
64  };
65
66  const registerValidator = (name, validate) => {
67    validators[name] = validate;
68  };
69
70  const validateField = (name) => {
71    if (validators[name]) {
72      const error = validators[name](values[name]);
73      setErrors(prev => ({ ...prev, [name]: error }));
74      return !error;
75    }
76    return true;
77  };
78
79  const validateAll = () => {
80    const newErrors = {};
81    let isValid = true;
82
83    Object.keys(validators).forEach(name => {
84      const error = validators[name](values[name]);
85      if (error) {
86        newErrors[name] = error;
87        isValid = false;
88      }
89    });
90
91    setErrors(newErrors);
92    return isValid;
93  };
94
95  const handleSubmit = (e) => {
96    e.preventDefault();
97    if (validateAll()) {
98      onSubmit(values);
99    }
100  };
101
102  const formValue = {
103    values,
104    errors,
105    validators,
106    setValue,
107    registerValidator,
108    validateField,
109    handleSubmit
110  };
111
112  return (
113    <FormContext.Provider value={formValue}>
114      <form onSubmit={handleSubmit}>
115        {children}
116      </form>
117    </FormContext.Provider>
118  );
119}
120
121// Usage example
122function RegistrationFormExample() {
123  const handleSubmit = (values) => {
124    console.log('Form submitted:', values);
125    alert('Registration completed successfully!');
126  };
127
128  return (
129    <div style={{ maxWidth: '400px', margin: '0 auto', padding: '20px' }}>
130      <h2>Registration Form</h2>
131
132      <FormProvider onSubmit={handleSubmit}>
133        <FormField
134          name="email"
135          label="Email"
136          type="email"
137          validate={(value) => {
138            if (!value) return 'Email is required';
139            if (!/S+@S+.S+/.test(value)) return 'Invalid email';
140            return '';
141          }}
142        />
143
144        <FormField
145          name="password"
146          label="Password"
147          type="password"
148          validate={(value) => {
149            if (!value) return 'Password is required';
150            if (value.length < 8) return 'Password must be at least 8 characters';
151            return '';
152          }}
153        />
154
155        <FormField
156          name="confirmPassword"
157          label="Confirm password"
158          type="password"
159          validate={(value) => {
160            const form = use(FormContext);
161            if (value !== form.values.password) return 'Passwords do not match';
162            return '';
163          }}
164        />
165
166        <button
167          type="submit"
168          style={{
169            width: '100%',
170            padding: '10px',
171            backgroundColor: '#007bff',
172            color: 'white',
173            border: 'none',
174            borderRadius: '4px',
175            fontSize: '16px',
176            cursor: 'pointer'
177          }}
178        >
179          Register
180        </button>
181      </FormProvider>
182    </div>
183  );
184}

Best practices with use

1. When to use use

1// GOOD - conditional usage
2function ConditionalData({ showDetails }) {
3  if (showDetails) {
4    const details = use(detailsPromise);
5    return <DetailView details={details} />;
6  }
7  return <Summary />;
8}
9
10// GOOD - in loops
11function MultipleResources({ resourceIds }) {
12  const resources = resourceIds.map(id => {
13    const promise = fetchResource(id);
14    return use(promise);
15  });
16  return <ResourceList resources={resources} />;
17}
18
19// BAD - unnecessary use for simple values
20function BadExample() {
21  const value = use(Promise.resolve(42)); // Unnecessary!
22  return <div>{value}</div>;
23}

2. Cache and optimization

1// Simple cache implementation
2const cache = new Map();
3
4function useCachedResource(key, fetcher) {
5  if (!cache.has(key)) {
6    cache.set(key, fetcher());
7  }
8
9  const promise = cache.get(key);
10  const resource = use(promise);
11
12  return resource;
13}
14
15// Usage
16function CachedDataComponent({ userId }) {
17  const userData = useCachedResource(
18    `user-${userId}`,
19    () => fetchUser(userId)
20  );
21
22  return <UserProfile user={userData} />;
23}

3. Error handling

1// Wrapper with retry logic
2function createRetryablePromise(fetcher, maxRetries = 3) {
3  return async () => {
4    let lastError;
5
6    for (let i = 0; i < maxRetries; i++) {
7      try {
8        return await fetcher();
9      } catch (error) {
10        lastError = error;
11        if (i < maxRetries - 1) {
12          // Exponential backoff
13          await new Promise(resolve =>
14            setTimeout(resolve, Math.pow(2, i) * 1000)
15          );
16        }
17      }
18    }
19
20    throw lastError;
21  };
22}
23
24// Usage
25function RobustDataFetching() {
26  const dataPromise = createRetryablePromise(
27    () => fetch('/api/critical-data').then(res => res.json())
28  )();
29
30  return (
31    <ErrorBoundary>
32      <Suspense fallback={<div>Loading...</div>}>
33        <DataComponent dataPromise={dataPromise} />
34      </Suspense>
35    </ErrorBoundary>
36  );
37}

The

use
hook opens new possibilities in React, allowing for more flexible management of asynchronous data and context. Its unique ability to be used conditionally and in loops makes it a powerful tool for advanced applications.

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