Claude Sonnet 5.5

Cause

Race condition: when you fire off a new fetch for each keystroke, slower older requests can resolve after newer ones, overwriting fresh results with stale data (since promises don't resolve in order).

Solution: Cancel stale requests with AbortController

function SearchBox() {
  const [query, setQuery] = useState('');
  const [results, setResults] = useState([]);

  useEffect(() => {
    if (!query) return;

    const controller = new AbortController();

    fetch(`/api/search?q=${query}`, { signal: controller.signal })
      .then(res => res.json())
      .then(setResults)
      .catch(err => {
        if (err.name !== 'AbortError') console.error(err);
      });

    return () => controller.abort(); // cancel previous request
  }, [query]);

  return (
    <input
      value={query}
      onChange={e => setQuery(e.target.value)}
    />
  );
}

How it works: Every time query changes, the effect cleanup aborts the in-flight request from the previous keystroke before starting a new one. Aborted requests throw an AbortError, which you ignore—ensuring only the latest request's results ever update state.

Upload failed due to an unexpected error

Hi there,

Unfortunately, your file upload did not complete successfully — an unexpected error occurred while processing your request. Your file was not saved, so please try uploading it again.

What to do next:

1. Check your internet connection.
2. Make sure the file meets any size/format requirements.
3. Retry the upload:

# Example: re-attempt the upload
curl -X POST https://example.com/api/upload \
  -F "file=@yourfile.ext"

If the problem continues after a couple of attempts, please contact our support team with the approximate time of the failed attempt and the file name — this will help us investigate faster.

Sorry for the inconvenience, and thanks for your patience!

Safe Rollout Plan

1. Add column (non-blocking)

ALTER TABLE users ADD COLUMN display_name VARCHAR(255) NULL;

Nullable, no default — avoids table rewrite/lock on most DBs (Postgres: fast; MySQL 8+/Aurora: online DDL).

2. Deploy app code (read-tolerant)

• Deploy app version that can read display_name if present but doesn't require it (ORM model updated, nullable field).
• No writes yet.

3. Backfill (if needed)

• Batch update in small chunks with throttling, off-peak:

UPDATE users SET display_name = COALESCE(first_name,'') 
WHERE id BETWEEN ? AND ? AND display_name IS NULL;

4. Enable writes

• Deploy app version that writes display_name on create/update.

5. (Optional) Enforce constraints later

• Only after backfill confirmed complete, consider NOT NULL/default in a separate migration.

Rollback

• App: redeploy previous version (ignores column — safe since nullable).
• DB: leave column in place (dropping is riskier); or ALTER TABLE users DROP COLUMN display_name; only if confirmed unused and low traffic.