AbortController for cancellation in Node.js - Mini Project: Build & Apply

Using AbortController for Cancellation in Node.js

📖 Scenario: You are building a Node.js script that fetches data from a slow API. Sometimes, the user wants to cancel the request if it takes too long.To handle this, you will use AbortController to cancel the fetch request after a timeout.

🎯 Goal: Create a Node.js script that fetches data from https://jsonplaceholder.typicode.com/todos/1 and cancels the request if it takes more than 2 seconds.

📋 What You'll Learn

Create an AbortController instance

Set a timeout to abort the fetch after 2 seconds

Use the signal from the controller in the fetch request

Handle the abort error gracefully

💡 Why This Matters

🌍 Real World

AbortController is useful in real apps to stop slow or unwanted network requests, improving user experience and saving resources.

💼 Career

Understanding AbortController is important for Node.js developers working with APIs, especially when building responsive and efficient applications.

1

Create an AbortController instance

Create a variable called controller and assign it a new AbortController() instance.

Node.js

# Your code here

Need a hint?

Use new AbortController() to create the controller.

2

Set a timeout to abort the controller

Create a timeout using setTimeout that calls controller.abort() after 2000 milliseconds.

Node.js

const controller = new AbortController();

# Your code here

Need a hint?

Use setTimeout with 2000 ms and call controller.abort() inside.

3

Fetch data with the abort signal

Write a fetch call to https://jsonplaceholder.typicode.com/todos/1 using await inside an async function called fetchData. Pass signal: controller.signal as an option to fetch.

Node.js

const controller = new AbortController();

setTimeout(() => {
    controller.abort();
}, 2000);

async function fetchData() {
    // Your code here
}

Need a hint?

Use fetch with the signal option from the controller.

4

Handle abort error and call fetchData

Call fetchData() and catch errors. If the error's name is 'AbortError', log 'Fetch aborted'. Otherwise, rethrow the error.

Node.js

const controller = new AbortController();

setTimeout(() => {
    controller.abort();
}, 2000);

async function fetchData() {
    const response = await fetch('https://jsonplaceholder.typicode.com/todos/1', { signal: controller.signal });
    const data = await response.json();
    return data;
}

// Your code here

Need a hint?

Use .catch on the promise returned by fetchData() to handle abort errors.