JavaScript Promise.race() Method

Hello guys, How are you?

Today in this tutorial, we will learn about the JavaScript Promise.race() method and how we can use it in an easy way.

JavaScript promise object based on two code points, the one is producing code and another is consuming code. When producing code returns the result then it should have to call the two callback functions success() and error().

Note: Producing code is that which will take some time to run and consuming code is that which has to wait for the result.

Let’s see how we can use the Promise.race() method in javascript.

Using Promise.race()

The Promise.race() method is used to set a time limit for a given task. We can set the timeout function for Promise requests.

Using the following code example, we can run a race between our timer Promise and the actual request that we want to run.

const fetchRequest = () => new Promise((resolve, reject) => {
   setTimeout(resolve, 5000);
});

const timer = (timeout) => new Promise((resolve, reject) => {
   setTimeout(() => reject(new Error("Time limit exceeded.")), timeout);
});

Promise.race([fetchRequest(), timer(10000)])
   .then(() => console.log("Success within time limit."))
   .catch(console.error);

In the above code, if our request promise is executed within the time limit, it will be considered a success otherwise it will return an error.

See Also: Filter() Function with JavaScript Array

Being Tricky 😉