Asynchronous programming is an essential part of Node.js development. It allows Node.js applications to handle multiple tasks simultaneously and efficiently. One of the most commonly used asynchronous techniques in Node.js is the use of async/await. However, there is an alternative to async/await that can speed up your API calls even further – Promises.allSettled().

Switching from Async/Await to Promises.allSettled()

In this article, we will discuss what Promises.allSettled() is, how it differs from async/await, and how you can use it to speed up your API calls in Node.js.

What is Promises.allSettled()?

Promises.allSettled() is a method that returns a Promise that resolves when all promises in an array of promises have settled, i.e., when all of the promises have either been fulfilled or rejected. Unlike Promise.all(), which rejects as soon as one promise in the array rejects, Promises.allSettled() waits for all promises to settle, regardless of their state.

How does Promises.allSettled() differ from async/await?

Async/await is a syntactic sugar on top of Promises. It allows developers to write asynchronous code in a synchronous style, making it easier to read and write. However, async/await is not always the most performant option.

When you use async/await to make multiple API calls, each API call is executed sequentially. This means that the second API call will not be executed until the first API call has completed. This can lead to slower performance, especially when you need to make multiple API calls simultaneousl

Promises.allSettled(), on the other hand, allows you to make multiple API calls simultaneously, without waiting for one API call to complete before starting the next one. This can significantly speed up your API calls, leading to faster performance overall.

How to use Promises.allSettled() to speed up API calls in Node.js

To use Promises.allSettled() to speed up your API calls in Node.js, you need to follow these steps:

Step 1: Create an array of promises

The first step is to create an array of promises that you want to execute simultaneously. Each promise should represent an API call that you want to make.

For example, if you want to make three API calls simultaneously, you can create an array of promises like this:

const promises = [
  makeApiCall1(),
  makeApiCall2(),
  makeApiCall3()
];

Step 2: Use Promises.allSettled()

The next step is to use Promises.allSettled() to execute all promises in the array simultaneously. This can be done using the following code:

Promise.allSettled(promises)
  .then(results => {
    // handle the results here
  })
  .catch(error => {
    // handle the error here
  });

The Promise.allSettled() method returns a promise that resolves with an array of objects representing the fulfillment state of each promise in the array. Each object has two properties: status and value.

The status property represents the fulfillment state of the promise and can be one of two values: fulfilled or rejected. The value property represents the value that the promise resolved with or the reason that the promise was rejected.

Step 3: Handle the results

The final step is to handle the results of the API calls. You can do this by iterating over the results array and checking the status property of each object.

For example, you can use the following code to iterate over the results array and log the result of each API call:

results.forEach(result => {
  if (result.status === 'fulfilled') {
console.log(API call successful with result: ${result.value});
} else {
console.log(API call failed with reason: ${result.reason});
}
});

By using Promises.allSettled() instead of async/await, you can make multiple API calls simultaneously, leading to faster performance and improved efficiency in your Node.js applications.

Conclusion

Promises.allSettled() is a powerful method that can help you speed up your API calls in Node.js. By allowing you to execute multiple API calls simultaneously, Promises.allSettled() can significantly improve the performance of your Node.js applications.

While async/await is a useful syntactic sugar for writing asynchronous code in a synchronous style, it is not always the most performant option. Promises.allSettled() offers an alternative that can speed up your API calls and improve the efficiency of your Node.js applications.

By following the steps outlined in this article, you can start using Promises.allSettled() to speed up your API calls in Node.js today.