Debugging is one of the crucial activities during software development. It refers to the process of identifying an error in a software application that causes performance issues, then analyzing the issue, and finally resolving it. Debugging allows you to validate your code and fix issues before pushing a software application into the production stage.

Coming to React Native debugging; the framework is made up of different environments, the most prominent being Android and iOS. As a result, it becomes challenging to debug apps due to the multiple platforms involved. But thanks to the vast number of contributors to the React Native ecosystem, many debugging tools are available. And here, we will discuss the ways to debug a React Native application.

“Only half of programming is coding. The other 90% is debugging.” —Anonymous

The different methods discussed in this article:

1. Consoles
2. Native logs
3. Debugging using VS Code
4. Browser developer tool
5. Reactotron
6. Flipper

1. Consoles

When it comes to debugging, console logs are really insightful, helping you examine the real-time data that an app is using at any point of execution.

To view Console logs, you need to run your app on the device; the Console logs will appear in the terminal process. It’s important to use the proper log level while writing logs. Besides the console.log, there are other log levels like console.warn, console.error, and advanced console.table, console.dir, etc. Each of these logs has a specific purpose and provides a more granular control on the level of information needed.

2. Native logs

According to the official React Native documentation, you can easily log reports for both platforms:

npx react-native log-ios
npx react-native log-android

If you need to go deeper, you can use platform-specific IDE like XCode or Android Studio to analyze the native code of the app and fix the problem.

3. Debugging using VS Code

The majority of React Native developers’ work is spent in Visual Studio Code, and jumping between the code and debugger can be annoying. Let me make this easier for you by introducing you to a more convenient way.

Debugging in React Native is not supported by VS Code by default. Just install “React Native Tools” under the Extensions menu. Choose “Build a launch.json file” from the Run & Debug Tab. Once you’ve added configuration for your iOS and Android apps, you’re ready to begin.

Using breakpoints similar to those in the Chrome debugger or native debugging in Android Studio or Xcode, you can debug line-by-line.

You can find the detailed article at: https://blog.logrocket.com/debugging-react-native-vs-code/

4. Browser developer tool

The default and basic debugger of react native is the browser-devtool.
No installation or special configuration is needed, simply open the debug menu of the phone you are working on and choose the debug option.

Open a Chrome browser tab with “http://localhost:8081/debugger-ui/” and under the “source” tab you will be able to debug scripts and components.

5. Reactotron

Reactotron is an open-source desktop app that allows you to inspect Redux or MobX-State-Tree application state as well as view custom logs, run custom commands such as resetting state, store and restore state snapshots, and other helpful debugging features for React Native apps.

It is one of the most effective tools for tracking API calls and responses. When your app interacts with an API, you can get a complete visual representation of the Response, Response Headers, Request Params, and Requested Headers.

Advantage of Reactotron It runs without debugger mode being turned on, so it doesn’t slow down your app.

6. Flipper

Flipper is a next-gen platform for debugging iOS, Android, and React Native applications. It is an open-source debugging tool developed by Facebook. It was introduced with default integration with the launch of React Native 0.62 and has evolved over time and is now a trusted, stable React Native Debugging Tool.

Flipper edits the components on the fly, then reflects those edits in real-time within the application, and integrates with the app’s Layout Inspector. Its capability of integrated launch management enables developers to define configurations and employ them for unit testing, without having to replicate configurations in several places. Moreover, comes with a plugin-based architecture and myriad handy features; more features are expected in the coming years.

With Flipper, you can view, inspect, and control your apps using a simple desktop interface. Flipper can be used as it is or extended by employing the plugin API.

Pro Tip: Flipper can be considered a fusion of all the methods listed above; it performs all those operations in a more efficient and effective manner.

Bottom Line

There are many different tools and methodologies that enable you to debug apps more efficiently and flawlessly, just like a pro. These tools and best practices work wonders to speed up development, enhance developer productivity, and improve the performance of the end product.

Keep experimenting and sharing your experience!
Happy coding!