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How To Implement NextJS Error Boundary & Best Practices To Follow

Written by Jack Dwyer | Jul 8, 2024 7:39:57 PM

Are you tired of encountering errors that disrupt the smooth functioning of your Next.js application? Picture this: just when your website is gaining popularity, a user encounters an error that leads to a negative experience. How can you prevent this from happening in the first place? If Learning about error boundary and how to handle errors in Next.js is your goal, you are in the right place because you will soon discover how Vercel logging can be a game-changer in managing NextJS error boundaries.

Alerty's NextJS logging solution is the answer to your troubles. This tool can help you identify and address errors effectively, making your journey towards learning about NextJS error boundary smoother.

Table of Contents

What Are Error Boundaries And How Do They Work In Next.js?

Error boundaries are a feature in NextJS that allows developers to handle better errors during the components' rendering phase. They help prevent the entire application from crashing and provide a fallback UI in case of errors. Error boundaries are implemented as higher-order components that wrap around a collection of components, creating an isolated error-catching zone.

How Do Error Boundaries Work?

Error boundaries in Next.js are a way to catch and handle errors in your application. They define a component that extends the ErrorBoundary class from the next/error-boundary. This component will catch errors within its child components and render a fallback UI instead of the component tree that crashed. 

The ErrorBoundary component can be used to catch errors in both server-side and client-side rendering. When an error occurs, the ErrorBoundary component will re-render with its fallback UI, allowing the rest of the application to continue running without crashing. This helps ensure your application remains stable and user-friendly even when errors occur.

When Should You Use Error Boundaries?

Error boundaries should be used when components may throw errors during rendering, but you want to prevent these errors from crashing the entire application. They are particularly useful when dealing with external dependencies, such as API calls or third-party libraries, where errors are harder to anticipate and control. By wrapping these potentially error-prone components with an error boundary, you can ensure a smooth user experience and provide helpful feedback.

Prerequisites For Error Handling In NextJS

To effectively handle errors in Next.js applications, you need to have a solid foundation in various areas. Below are the prerequisites you should have to get the best out of error boundaries and handling in Next.js

Basic Knowledge of JavaScript

Understanding JavaScript basics is crucial as it forms the backbone of any code you write in Next.js. Error handling also relies on your understanding of JavaScript concepts, so ensure you grasp this language well.

Basic Knowledge of React and Next.js

Since Next.js is built on top of React, a sound understanding of React will be useful when implementing error boundaries. You need to know how React components work and how they can be used to catch errors in your application.

Basic Knowledge of Testing JavaScript Libraries and Frameworks

Testing is a crucial aspect of software development, and error boundaries in Next.js are no exception. You should be familiar with testing libraries and frameworks in JavaScript as they help you ensure your error boundaries work as expected.

Focus on Development, Leave Error Monitoring to Alerty

Are you using Next.js and need a reliable tool to handle and monitor application errors? Check out [Alerty](#), a cloud monitoring service that offers application performance monitoring, database monitoring, and incident management, including support for technologies like NextJS. 

Alerty helps you identify and fix issues quickly so you can stay focused on building your application without worrying about unexpected errors. 

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Implementing Error Boundary In Next.js

Setting Up Error Boundaries

To implement error handling in your Next.js application, the first step is to create an ErrorBoundary component. This component will catch JavaScript errors in its child component tree, log them, and display a fallback UI instead of letting the error crash the application. 

Here’s how you can create a basic ErrorBoundary component:

// components/ErrorBoundary.js

import React, { Component } from 'react';

 

class ErrorBoundary extends Component {

  constructor(props) {

    super(props);

    this.state = { hasError: false };

  }

 

  static getDerivedStateFromError(error) {

    // Update state so the next render shows the fallback UI

    return { hasError: true };

  }

 

  componentDidCatch(error, errorInfo) {

    // Log the error to an error reporting service console

    console.error('Error caught by Error Boundary:', error, errorInfo);

  }

 

  render() {

    if (this.state.hasError) {

      // You can render any custom fallback UI

      return <h1>Something went wrong.</h1>;

    }

 

    return this.props.children;

  }

}

 

export default ErrorBoundary;

In this component, getDerivedStateFromError updates the state to show a fallback UI when an error occurs. The componentDidCatch method logs the error, which can also be sent to an error-reporting service console.

Integrating Error Boundaries in Next.js App

To integrate the ErrorBoundary component into your Next.js application, you can wrap your root component with it. This ensures that the error boundary catches any error within the application. 

Here’s how to do it in the _app.js file:

 

// pages/_app.js

import ErrorBoundary from '../components/ErrorBoundary';

import '../styles/globals.css';

 

function MyApp({ Component, pageProps }) {

  return (

    <ErrorBoundary>

      <Component {...pageProps} />

    </ErrorBoundary>

  );

}

 

export default MyApp;

By wrapping the Component with ErrorBoundary, you ensure that all errors within your app’s component tree are caught and handled, improving error handling in your Next.js app.

Enhancing Error Handling

Handling Errors in Development

During the development phase of a Next.js application, encountering runtime errors triggers an overlay. This overlay is a modal on the webpage and provides vital information on the error. Developers can only view this overlay when running the development server using specific commands like:

  • next dev
  • pnpm dev
  • npm run dev
  • yarn dev
  • bun dev

Improving the error leads to the automatic dismissal of the overlay.

Handling Server Errors

Next.js has a default static 500 page to manage server-side errors within your application. You can customize this static page by creating a 500.js file within the pages directory. Utilizing a 500 page ensures that specific errors remain hidden from app users, preserving a seamless user experience.

Handling Client Errors

Client components run in the browser and are prone to client-side errors. Using an error boundary, you can handle these errors gracefully. 

For example:

// components/ClientComponent.js

import React from 'react';

 

function ClientComponent() {

  if (true) {

    throw new Error('Client-side error occurred');

  }

 

  return <div>Client Component Content</div>;

}

 

export default ClientComponent;

By wrapping ClientComponent with ErrorBoundary, you catch errors in client components and display a fallback UI instead of breaking the entire app.

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Advanced Error Handling Techniques In NextJS

Integrating an error reporting service console in your Next.js application allows you to track and log errors effectively. This integration helps monitor and debug by providing detailed reports of where and why errors occurred. Popular error-reporting services include:

  • Alerty
  • Sentry
  • LogRocket

Sending Errors to Reporting Service

To send errors to your reporting service, use the `componentDidCatch` method in your ErrorBoundary component. This method captures the error and sends it to the service.

Setting Up Global Error Boundaries

Global error boundaries ensure that errors anywhere in your application are caught and handled gracefully. You can configure global error boundaries by wrapping the main app component in `_app.js`.

Managing Server-Side Errors and Logs

Server-side errors in Next.js can be managed by customizing the `getInitialProps` lifecycle method in the `_error.js` page. This method allows you to log server-side errors and display custom error messages.

Testing Error Boundaries

Testing error boundaries ensures that your application can handle errors gracefully under different scenarios. Some popular testing libraries include:

  • Jest: A JavaScript testing framework
  • React Testing Library: A library for testing React components.

Strategies for Effective Error Boundary Testing

Effective error boundary testing involves simulating errors and verifying that the fallback UI is displayed correctly. Here’s an example of how to test an error boundary using Jest and React testing library:

Install necessary libraries

npm install @testing-library/react @testing-library/jest-dom jest

 

Write the test for ErrorBoundary:

// components/ErrorBoundary.test.js

import React from 'react';

import { render, screen } from '@testing-library/react';

import '@testing-library/jest-dom';

import ErrorBoundary from './ErrorBoundary';

 

const ProblemChild = () => {

  throw new Error('Test error');

};

 

test('renders fallback UI when an error occurs', () => {

  render(

    <ErrorBoundary>

      <ProblemChild />

    </ErrorBoundary>

  );

 

  expect(screen.getByText('Something went wrong.')).toBeInTheDocument();

});​

This test ensures that the ErrorBoundary component catches the error thrown by ProblemChild and displays the fallback UI.

3 Best Practices For Implementing NextJS Error Boundary

While using error boundaries in your NextJS applications, following certain best practices is crucial to ensure their effectiveness and maintainability. Here are some guidelines to consider:

1. Limit Error Boundary Scope

Wrapping only the necessary components with error boundaries is a good practice. Wrapping the entire application or large portions may make it harder to debug and pinpoint the source of errors. Instead, focus on the components that are more prone to errors or interact with external dependencies.

2. Provide User-Friendly Error Messages

When an error is caught by an error boundary, it’s essential to provide clear and user-friendly error messages to the users. Avoid showing technical details, or stack traces directly to the users, as they may not understand them. Instead, display a concise and helpful message that guides them on what went wrong and how to resolve the issue.

3. Test Error Scenarios

To ensure error boundaries are working as expected, testing the error scenarios in your application is crucial. Try to simulate different error conditions and verify if the error boundaries properly catch and handle the errors. This will help you identify any potential issues and improve the resilience of your application.

Catch Issues Before They Affect Your Users with Alerty's NextJS Logging Tool

Alerty is a cutting-edge cloud monitoring service tailored for developers and early-stage startups. It offers various features to ensure optimal application performance and incident management. Alerty supports a wide range of technologies, including:

  • NextJS, React
  • Vue
  • Node.js

The platform monitors essential databases such as Supabase, PostgreSQL, and RDS, keeping track of vital metrics like CPU usage and memory consumption. Alerty has a rapid incident management system to help developers quickly identify and resolve issues before they escalate. Real User Monitoring (RUM) is also integrated into the system to improve user experience by tracking user interactions and performance metrics.

Universal Service Monitoring for NextJS Error Boundaries

One of the distinctive features of Alerty is its universal service monitoring, which covers a broad range of dependencies crucial for web applications. From monitoring the performance of APIs like Stripe and OpenAI to ensuring the smooth running of services like Vercel, Alerty has got you covered. This universal approach enhances the overall application reliability and performance by providing visibility into the dependencies that your application relies on.

Simplified Setup and Cost-Effectiveness

Alerty sets itself apart by utilizing AI to simplify the setup process, allowing developers to start monitoring their applications effortlessly. This user-friendly design is ideal for developers and small teams seeking efficient and affordable monitoring solutions. Compared to its competitors, Alerty provides a cost-effective solution without compromising functionality or features, making it a go-to choice for businesses of all sizes. 

Integration with Sentry for Seamless Monitoring

Alerty seamlessly integrates with popular developer tools like Sentry, streamlining the monitoring process for better efficiency. This integration enables teams to centralize their monitoring efforts, making managing and resolving issues promptly easier. By leveraging the power of integration, Alerty ensures a smooth monitoring experience that aligns with the needs of modern development teams. 

Optimize User Experience with Real-Time Monitoring

Alerty's Real User Monitoring (RUM) feature allows developers to capture real-time data on user interactions, helping them understand how users interact with their applications. By gaining valuable insights into user behavior, developers can fine-tune their applications and deliver an optimized user experience. 

Alerty's focus on user-centric monitoring makes it a valuable tool for developers looking to enhance their applications.

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