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I'll search for the most current best practices on handling async/await errors in JavaScript to provide you with comprehensive guidance. Proper error handling with async/await in JavaScript is crucial for building robust applications. Here's a comprehensive guide covering best practices and techniques to handle asynchronous errors effectively.

Basic Try-Catch Pattern

The fundamental approach for handling async/await errors uses try-catch blocks:

async function fetchData(url) {
  try {
    const response = await fetch(url);
    const data = await response.json();
    return data;
  } catch (error) {
    console.error('Fetch error:', error);
    throw error; // Re-throw if needed
  }
}

Best Practices for Error Handling

1. Always Use Try-Catch Blocks

Wrap await statements in try-catch to prevent unhandled promise rejections:

async function safeAsyncOperation() {
  try {
    const result = await someAsyncFunction();
    return result;
  } catch (error) {
    // Handle error appropriately
    return null; // or default value
  }
}

2. Check HTTP Response Status

Fetch API doesn't automatically throw errors for HTTP error statuses:

async function fetchWithErrorChecking(url) {
  try {
    const response = await fetch(url);
    
    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }
    
    const data = await response.json();
    return data;
  } catch (error) {
    console.error('Request failed:', error);
    throw error;
  }
}

3. Use Finally Blocks for Cleanup

Ensure cleanup code runs regardless of success or failure:

async function processData() {
  let connection;
  try {
    connection = await establishConnection();
    const result = await processWithConnection(connection);
    return result;
  } catch (error) {
    console.error('Processing failed:', error);
    throw error;
  } finally {
    if (connection) {
      await connection.close();
    }
  }
}

4. Handle Multiple Async Operations

For concurrent operations, use Promise.all with proper error handling:

async function fetchMultipleResources() {
  try {
    const [users, posts, comments] = await Promise.all([
      fetchUsers(),
      fetchPosts(),
      fetchComments()
    ]);
    
    return { users, posts, comments };
  } catch (error) {
    console.error('One or more requests failed:', error);
    // Handle partial failure scenarios
    throw error;
  }
}

For handling partial failures, consider Promise.allSettled:

async function fetchWithPartialFailure() {
  const results = await Promise.allSettled([
    fetchUsers(),
    fetchPosts(),
    fetchComments()
  ]);
  
  const successful = results
    .filter(result => result.status === 'fulfilled')
    .map(result => result.value);
    
  const failed = results
    .filter(result => result.status === 'rejected')
    .map(result => result.reason);
    
  if (failed.length > 0) {
    console.warn('Some requests failed:', failed);
  }
  
  return successful;
}

Advanced Error Handling Patterns

Error Wrapper Function

Create reusable error handling utilities:

function asyncErrorWrapper(fn) {
  return async function(...args) {
    try {
      return await fn(...args);
    } catch (error) {
      console.error(`Error in ${fn.name}:`, error);
      throw error;
    }
  };
}

const safeApiCall = asyncErrorWrapper(async (url) => {
  const response = await fetch(url);
  return response.json();
});

Specific Error Types

Handle different error types appropriately:

async function handleSpecificErrors() {
  try {
    const data = await fetchData();
    return data;
  } catch (error) {
    if (error instanceof TypeError) {
      console.error('Network or parsing error:', error);
    } else if (error.name === 'AbortError') {
      console.error('Request was aborted:', error);
    } else {
      console.error('Unexpected error:', error);
    }
    
    throw error;
  }
}

Retrying Failed Operations

Implement retry logic for transient failures:

async function retryOperation(operation, maxRetries = 3, delay = 1000) {
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
      return await operation();
    } catch (error) {
      if (attempt === maxRetries) {
        throw error;
      }
      
      console.warn(`Attempt ${attempt} failed, retrying in ${delay}ms...`);
      await new Promise(resolve => setTimeout(resolve, delay));
      delay *= 2; // Exponential backoff
    }
  }
}

React/Frontend Integration

When using async/await in React components:

const MyComponent = () => {
  const [data, setData] = useState(null);
  const [error, setError] = useState(null);
  const [loading, setLoading] = useState(false);

  useEffect(() => {
    const loadData = async () => {
      setLoading(true);
      setError(null);
      
      try {
        const fetchedData = await fetchData('/api/data');
        setData(fetchedData);
      } catch (error) {
        setError(error.message);
      } finally {
        setLoading(false);
      }
    };

    loadData();
  }, []);

  if (loading) return <div>Loading...</div>;
  if (error) return <div>Error: {error}</div>;
  return <div>{data && data.content}</div>;
};

Key Guidelines

Variable Scope Management

When you need to use results outside the try block, declare variables beforehand:

async function processUser(userInfo) {
  let createdUser;
  
  try {
    createdUser = await User.create(userInfo);
  } catch (error) {
    console.error('User creation failed:', error);
    return null;
  }
  
  // Business logic continues here with createdUser
  return createdUser;
}

Don't Suppress Errors Silently

Always log errors and decide whether to re-throw:

// Good
try {
  const result = await riskyOperation();
  return result;
} catch (error) {
  console.error('Operation failed:', error);
  // Decide: return default value, re-throw, or handle gracefully
  throw error;
}

// Avoid silent failures
try {
  await riskyOperation();
} catch (error) {
  // Silent failure - bad practice
}

These patterns ensure your async JavaScript code handles errors gracefully, provides meaningful feedback to users, and maintains application stability even when network requests or other asynchronous operations fail [Source: https://codefinity.com/blog/Error-Handling-with-Async-Await-in-JavaScript] [Source: https://medium.com/@sudhirkmr529/mastering-error-handling-with-async-await-in-javascript-cb1c877bb554].