ts-safe-promise

A lightweight utility for handling promises safely without the need for try...catch. This package returns both error and result in a predictable format, simplifying asynchronous error handling in JavaScript and TypeScript.

Installation

npm install ts-safe-promise

Or with yarn:

yarn add ts-safe-promise

Example

• Import safePromise and use it to handle async functions without try...catch:

import { safePromise } from 'ts-safe-promise';

async function fetchData() {
	const [error, data] = await safePromise(fetchDataFromAPI());

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

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

Why ts-safe-promise?

In JavaScript, handling asynchronous operations often involves using try...catch blocks around await statements. While effective, this approach has a few downsides:

1. Verbosity: Every time you need to handle errors, you end up writing try...catch around each async function, making code longer and less readable.
2. Nested Error Handling: When chaining multiple promises, try...catch becomes cumbersome and may lead to nested error handling.
3. Inconsistent Results: Without try...catch, an unhandled promise rejection can crash your application, making it necessary to handle errors carefully in every async call.

Example Problem

Using try...catch repeatedly can clutter your code:

async function fetchData() {
	try {
		const data = await fetchDataFromAPI();
		return data;
	} catch (error) {
		console.error('Error fetching data:', error);
		return null;
	}
}

With multiple await statements, this can get repetitive and harder to read:

async function performActions() {
	try {
		const data1 = await fetchDataFromAPI1();
		const data2 = await fetchDataFromAPI2(data1);
		const result = await processData(data2);
		return result;
	} catch (error) {
		console.error('Error performing actions:', error);
	}
}

How ts-safe-promise Solves This

• ts-safe-promise offers a simpler way to handle asynchronous operations by ensuring every Promise returns in a consistent [error, data] format:

• Consistent Results: Each async function call always returns either [undefined, result] (on success) or [error, undefined] (on failure).

• Readable Code: Avoids try...catch, allowing for more readable and maintainable code. Flexible Error Handling: Handle errors directly in the response without needing to wrap each call.

Usage

import { safePromise } from 'ts-safe-promise';

async function performActions() {
	const [error1, data1] = await safePromise(fetchDataFromAPI_1());
	if (error1) {
		console.error('Error fetching data 1:', error1);
		return;
	}

	const [error2, data2] = await safePromise(fetchDataFromAPI_2(data1));
	if (error2) {
		console.error('Error fetching data 2:', error2);
		return;
	}

	const [error3, result] = await safePromise(processData(data2));
	if (error3) {
		console.error('Error processing data:', error3);
		return;
	}

	console.log('Result:', result);
}

API

• safePromise(promise: Promise): Promise<[Error, undefined] | [undefined, T]>
• Parameters: Accepts a promise that resolves with type T.
• Returns: A promise resolving to [undefined, result] if successful, or [error, undefined] if failed.

License

MIT License.