Replace Callbacks by Async/Await

Refactor this JavaScript code to use async/await instead of callbacks for handling asynchronous operations. The goal is to improve code readability and error handling.

function fetchData(url, callback) {
  http.get(url, function(response) {
    let data = '';
    response.on('data', (chunk) => {
      data += chunk;
    });
    response.on('end', () => {
      callback(null, data);
    });
  }).on('error', (err) => {
    callback(err);
  });
}

async function fetchData(url) {
try {
const response = await new Promise((resolve, reject) => {
http.get(url, (res) => {
let data = '';
res.on('data', (chunk) => {
data += chunk;
});
res.on('end', () => {
resolve(data);
});
}).on('error', reject);
});
return response;
} catch (error) {
throw error; // Re-throw the error to be handled by the caller
}
}

Explanation:

1. async function: We define the fetchData function as async, allowing us to use await within it.
2. try...catch block: We wrap the asynchronous operation in a try...catch block to handle potential errors.
3. Promise and await:
4. We create a Promise that resolves with the data when the response is fully received.
5. We use await to pause the execution of the function until the Promise resolves.
6. Error handling:
7. If an error occurs during the http.get request, the reject function of the Promise is called, causing the catch block to execute.
8. We re-throw the error using throw error to propagate it to the caller.
9. Return value: The fetchData function returns the fetched data if successful.

Usage:

async function main() {
try {
const data = await fetchData('https://example.com/data');
console.log(data);
} catch (error) {
console.error('Error fetching data:', error);
}
}

main();

Benefits of using async/await:

• Improved readability: The code is more concise and easier to understand, as the asynchronous flow is more explicit.
• Simplified error handling: The try...catch block provides a clear way to handle errors.
• No callback hell: We avoid nested callbacks, making the code more maintainable.
• Better control flow: The code execution is more predictable, as await pauses the function until the asynchronous operation completes.