TypeScript

Mastering Async/Await Error Handling

Write resilient asynchronous code with clean, predictable error handling patterns.

6 min readJun 2, 2026

The Problem with Unhandled Promises

When an awaited promise rejects, the error propagates up the call stack. Without a try/catch, you get an unhandled rejection that can crash your process or silently swallow failures.

A Clean try/catch Pattern

Wrap your awaited calls in a try/catch and rethrow after logging so callers can still react to the failure.

TypeScript

async function fetchData() {
  try {
    const response = await fetch('/api/data');
    if (!response.ok) throw new Error('Bad response');
    return await response.json();
  } catch (error) {
    console.error('Failed:', error);
    throw error;
  }
}

Going Further with Result Types

For predictable control flow, return a tuple of [error, data] instead of throwing. This forces callers to handle the error path explicitly.

TypeScript

async function safe<T>(p: Promise<T>): Promise<[Error | null, T | null]> {
  try {
    return [null, await p];
  } catch (e) {
    return [e as Error, null];
  }
}