Best Practices for Error Handling with Async/Await in Web Applications

[reboottime]

Practices about error handling using async, await in a web app

Although async and await provide convenient and more transparent logic flows in code, improper usage or inadequate error handling can make an async, await codebase difficult to debug at times.

Therefore, consider adhering to the following best practices to enhance your code's reliability and maintainability:

1. Use try/catch blocks: When calling an asynchronous function using the await keyword, wrap it in a try/catch block to handle any errors thrown by the function. This will allow you to catch and handle errors controlled and predictably.

2. Use Promise rejection: When an asynchronous function encounters an error, it should reject the Promise it returns with an error object. You can then use the .catch() method to handle the calling code error.

3. Throw meaningful error messages: When throwing an error in your asynchronous code, include a descriptive error message that explains the problem. This will help you debug the code and provide useful feedback to the user if necessary.

4. Use a centralized error handler: Rather than handling errors in each individual component or function, it's often more efficient to use a centralized error handler to manage errors globally. This will allow you to manage errors more easily and avoid duplicating error handling code throughout your application.

5. Handle network errors: When working with asynchronous code that makes network requests, it's important to handle network errors gracefully. This can include displaying a user-friendly error message, retrying failed requests, or implementing fallback strategies.

6. Test error handling: Make sure to test your error handling code thoroughly to ensure that it works as expected in all situations. This can include testing error scenarios, edge cases, and different network conditions.

By following these best practices, we can create more reliable and maintainable asynchronous JavaScript code that handles errors effectively and provides a better user experience.

---

One unpleasant experience you might have had

const result1 = await getFirstRequest();

const result2 = await getSecondRequest();

const result3 = await getThirdRequest();

If the getFirstRequest() function fails, subsequent requests will not be executed. This can be problematic in a large codebase with complex logic flows, as it could be cumbersome to identify which step caused the final failure, especially if the error occurs silently.

---

Handling network errors

When a request fails due to a network issue, for example, when the browser loses internet access due to a WIFI problem, the request result fails as well.

To handle such situations, wrap your request action in a try catch block. For example

async function fetchUserData(userId: string): Promise<User> {

  try {

    const response = await fetch(`https://api.example.com/users/${userId}`);

    if (!response.ok) {

      // Handle non-2xx HTTP response status codes

      throw new Error(`HTTP error! Status: ${response.status}`);

    }

    const user = await response.json();

    return user;

  } catch (error) {

    // Handle network errors, server errors, or other errors

    console.error(`Error fetching user data: ${error.message}`);

    throw error;

  }

}