Error Handling with Axios

Error handling is an essential aspect of building robust and reliable applications, especially when working with external APIs. In this tutorial, we will explore how to handle errors effectively using Axios, a popular JavaScript library for making HTTP requests.

Understanding Axios Errors

Axios provides a comprehensive error handling mechanism that allows you to catch and handle errors in a centralized manner. When an error occurs, Axios returns an error object that contains information about the error, including the status code, response data, and more.

Using Catch Blocks

One way to handle errors with Axios is by using catch blocks. A catch block is used to catch any errors that occur during the execution of a promise. Here’s an example:

axios.get('/api/endpoint')
  .then((response) => {
    console.log(response.data);
  })
  .catch((error) => {
    if (error.response) {
      // The request was made and the server responded with a status code
      // that falls out of the range of 2xx
      console.log(error.response.data);
      console.log(error.response.status);
      console.log(error.response.headers);
    } else if (error.request) {
      // The request was made but no response was received
      // `error.request` is an instance of XMLHttpRequest in the browser 
      // and an instance of http.ClientRequest in node.js
      console.log(error.request);
    } else {
      // Something happened in setting up the request that triggered an Error
      console.log('Error', error.message);
    }
  });

In this example, we’re using a catch block to catch any errors that occur during the execution of the Axios request. We’re then checking if the error has a response property, which indicates that the server responded with a status code outside of the range of 2xx.

Using Async/Await

Another way to handle errors with Axios is by using async/await syntax. Here’s an example:

async function makeRequest() {
  try {
    const response = await axios.get('/api/endpoint');
    console.log(response.data);
  } catch (error) {
    if (error.response) {
      // The request was made and the server responded with a status code
      // that falls out of the range of 2xx
      console.log(error.response.data);
      console.log(error.response.status);
      console.log(error.response.headers);
    } else if (error.request) {
      // The request was made but no response was received
      // `error.request` is an instance of XMLHttpRequest in the browser 
      // and an instance of http.ClientRequest in node.js
      console.log(error.request);
    } else {
      // Something happened in setting up the request that triggered an Error
      console.log('Error', error.message);
    }
  }
}

In this example, we’re using async/await syntax to make the Axios request. We’re then using a try/catch block to catch any errors that occur during the execution of the request.

Using Interceptors

Axios also provides an interceptor mechanism that allows you to intercept requests and responses globally. Here’s an example:

axios.interceptors.response.use(
  (response) => {
    // Optional: Do something with response data
    return response;
  },
  (error) => {
    // Do whatever you want with the response error here:

    // But, be SURE to return the rejected promise, so the caller still has 
    // the option of additional specialized handling at the call-site:
    return Promise.reject(error);
  }
);

In this example, we’re using an interceptor to catch any errors that occur during the execution of Axios requests. We’re then checking if the error has a response property and logging the error data accordingly.

Best Practices

Here are some best practices for handling errors with Axios:

• Always use catch blocks or try/catch syntax to handle errors.
• Check if the error has a response property to determine if the server responded with a status code outside of the range of 2xx.
• Use interceptors to catch errors globally and provide a centralized error handling mechanism.
• Always return the rejected promise from an interceptor so that the caller can still handle the error.

By following these best practices, you can ensure that your application handles errors effectively and provides a robust user experience.