Callbacks & Callback Hell

What safety mechanism does this code implement?

function withTimeout(fn, timeout) {
  return function(arg, callback) {
    let timeoutId = setTimeout(() => {
      callback(new Error('Operation timed out'));
      callback = () => {}; // Prevent double callback
    }, timeout);
    
    fn(arg, (err, result) => {
      clearTimeout(timeoutId);
      callback(err, result);
    });
  };
}

Error handling
Timeout handling
This code implements timeout handling for async operations. Key features: 1) Automatically fails the operation if it takes too long, 2) Prevents memory leaks by clearing the timeout, 3) Ensures callback is only called once using the nulling pattern, 4) Maintains the error-first callback pattern, 5) Can wrap any callback-based async function. This pattern is crucial for preventing hanging operations and implementing reliable timeouts.
Memory management
Callback validation

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