How do I handle errors with Promise.all in Node.js?

How do I handle errors with Promise.all in Node.js?

In Node.js, when using Promise.all, if one promise rejects, the entire Promise.all will reject. You can handle errors by using try-catch in an async function or by chaining a .catch() method.

Can you give me an example of that?

Sure! Here's a simple example:

async function fetchData() {
    try {
        const results = await Promise.all([
            fetch(url1),
            fetch(url2),
            fetch(url3)
        ]);
        // Process results
    } catch (error) {
        console.error('Error fetching data:', error);
    }
}

This way, if any fetch fails, it will be caught in the catch block.

What if I want to handle errors for each promise individually?

You can use Promise.allSettled instead. It will wait for all promises to settle, regardless of their outcome. Here's an example:

const results = await Promise.allSettled([
    fetch(url1),
    fetch(url2),
    fetch(url3)
]);
results.forEach((result) => {
    if (result.status === 'fulfilled') {
        console.log('Success:', result.value);
    } else {
        console.error('Error:', result.reason);
    }
});