@marcuth/promise

A simple, lightweight utility to handle Promises in TypeScript without repetitive try/catch blocks. Inspired by Go's error handling pattern.

🚀 Motivation

Working with Promises in JavaScript/TypeScript usually involves using try/catch, which can make code nested and harder to read when multiple asynchronous operations are involved.

// Without @marcuth/promise
try {
  const user = await getUser(id);
  try {
    const posts = await getPosts(user.id);
  } catch (err) {
    // handle posts error
  }
} catch (err) {
  // handle user error
}

With @marcuth/promise, you can handle errors in a linear and clean way:

import promise from '@marcuth/promise';

const [user, userErr] = await promise(getUser(id));
if (userErr) return handleError(userErr);

const [posts, postsErr] = await promise(getPosts(user.id));
if (postsErr) return handleError(postsErr);

📦 Installation

npm install @marcuth/promise
# or
yarn add @marcuth/promise
# or
pnpm add @marcuth/promise

🛠️ Usage

import promise from '@marcuth/promise';

async function fetchData() {
  const [data, error] = await promise(axios.get('https://api.example.com/data'));

  if (error) {
    console.error('Error fetching data:', error);
    return;
  }

  console.log('Received data:', data);
}

📖 API

promise<T>(p: Promise<T>): Promise<[T, null] | [null, any]>

The function takes a Promise and returns a tuple (two-element array):

1. Success: [Awaited<T>, null] - Where the first element is the result of the resolved Promise.
2. Error: [null, any] - Where the second element is the error caught in the catch block.

🧪 Development

If you want to contribute or test locally:

Install dependencies:

npm install

Run tests:

npm test

Build:

npm run build

📄 License

MIT