fetchWithRetry Promise

JavaScript

Medium

Objective

Write a function that takes a URL as a parameter, and returns a promise. The function should make an HTTP GET request to the provided URL.

If the request succeeds: the promise should resolve with the response data.
If the request fails: the function should wait for 1 second and try again. It should retry the request up to 3 times before rejecting the promise.

Requirements

The function should be called fetchWithRetry
It should take a single parameter which is a URL
It should make a GET request to the URL
If the request fails, you should retry it up to 3 times with a 1-second delay
The function should return a promise
1. If data is successfully received from the endpoint, the promise should resolve with the data
2. If the request fails 3 times, the promise should reject with an error message
You should not use any libraries (e.g. axios) to complete this task

Check your solution

Tests

Function name is fetchWithRetry
fetchWithRetry("https://www.example.com")	Expected:	"fetch data successfully on first try"
fetchWithRetry("http://www.example.com")	Expected:	"should retry and succeed on the second attempt"
fetchWithRetry("www.example.com")	Expected:	"should reject after 3 attempts"

Solution

Here's how I would approach this, but keep in mind there might be other ways to solve this problem.


function fetchWithRetry (url) {
    const maxRetries = 3;
    let retries = 0;

    // Return a promise
    return new Promise((resolve, reject) => {
        function fetchUrl () {
            fetch(url)
                .then(response => {
                    // Check if 200 OK
                    if (response.ok) {
                        resolve(response);
                    } else {
                        // Retry
                        retries++;
                        if (retries >= maxRetries) {
                            // We've reached the maximum number of retries, reject the promise
                            reject(new Error('Maximum number of retries reached'));
                        } else {
                            // Try again after 1 second
                            setTimeout(fetchUrl, 1000);
                        }
                    }
                })
                .catch(reject);
        }

        fetchUrl();
    });
}

Click to reveal