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typescript.async_without_error_handling

Stability High

Detects async functions without proper error handling that can cause unhandled rejections.

Why It Matters

Unhandled async errors:

Silent failures — Errors swallowed without logging
Process crash — Unhandled rejections terminate Node.js
Debugging nightmare — No stack trace, no context

Example

// ❌ Before (no error handling)
async function fetchUser(id: string): Promise<User> {
  const response = await fetch(`/users/${id}`);
  return response.json();
}

// Called without catch
fetchUser("123").then(user => console.log(user));

// ✅ After (with error handling)
async function fetchUser(id: string): Promise<User> {
  try {
    const response = await fetch(`/users/${id}`);
    if (!response.ok) {
      throw new Error(`HTTP ${response.status}`);
    }
    return response.json();
  } catch (error) {
    logger.error('Failed to fetch user', { id, error });
    throw error;
  }
}

// Or handle at call site
fetchUser("123")
  .then(user => console.log(user))
  .catch(error => logger.error('Fetch failed', error));

What Unfault Detects

Async functions without try-catch
Promise chains without .catch()
Fire-and-forget async calls