attemptAsync

Executes an async function and returns the result or error as a tuple.

const [error, result] = await attemptAsync(func);

Reference

attemptAsync(func)

Use attemptAsync when you want to safely execute an async function. You can handle errors without wrapping async/await blocks in try-catch.

import { attemptAsync } from 'es-toolkit/util';

// When API request succeeds
const [error, data] = await attemptAsync(async () => {
  const response = await fetch('https://api.example.com/data');
  return response.json();
});
// error is null, data contains response data

// When network error occurs
const [error, data] = await attemptAsync(async () => {
  throw new Error('Network error');
});
// error is Error object, data is null

// You can also specify types
interface User {
  id: number;
  name: string;
}

const [error, users] = await attemptAsync<User[]>(async () => {
  const response = await fetch('https://api.example.com/users');
  return response.json();
});
// users is inferred as User[] type

It's especially useful when you need error handling in async operations like database queries or file reading.

// File reading example
const [error, content] = await attemptAsync(async () => {
  const fs = await import('fs/promises');
  return fs.readFile('config.json', 'utf8');
});

if (error) {
  console.log('Cannot read file:', error.message);
} else {
  console.log('File content:', content);
}

Use attempt for synchronous functions

This function is suitable for handling async functions (functions that return Promise). If you want to handle synchronous functions, we recommend using the attempt function instead.

Parameters

• func (() => Promise<T>): The async function to execute.

Returns

(Promise<[null, T] | [E, null]>): Returns a Promise that resolves to [null, result] on success, or [error, null] if an error occurs.