Building error-free Node.js applications is crucial for delivering a seamless user experience. However, debugging can be a daunting task, especially for beginners. This blog post provides a comprehensive guide to essential Node.js debugging techniques, empowering you to identify and resolve errors effectively, ensuring your applications run smoothly and efficiently.
Debugging a NodeJS application can be done in several ways, including using the built-in command-line debugger, Visual Studio Code, JetBrains WebStorm, and other JetBrains IDEs, and the Node.js debugger client.
Variant to debug NodeJS application
- Using the built-in command-line debugger:
Start the script under the built-in command-line debugger by running
node debug script_name.js. This will start your script in another Node.js process started with the
--debug-brkswitches. You can then use the debugger commands to step through your code and inspect variables.
- Using Visual Studio Code:
launch.jsonfile and add a configuration to start your program or attach to a process launched outside of VS Code. You can also use the
Add Configuration...button in the lower right of the
launch.jsoneditor window to bring up snippets for commonly used Node.js debugging scenarios.
- Using JetBrains WebStorm:
Run your application with an
--inspect-brkflag, and set breakpoints in the code where necessary. You can then create a Node.js run/debug configuration and start the debugger from the built-in Terminal or from the Run or Debug tool window. You can also debug an already running application with the Chrome Debugging Protocol or with the V8 Debugging Protocol.
- Using the Node.js debugger client:
Start Node.js with the
inspectargument followed by the path to the script to debug, like this:
$ node inspect myscript.js. This will start the debugger client, which is not a full-featured debugger but allows for simple stepping and inspection. You can then use the debugger commands to step through your code and inspect variables.
In addition to these methods, you can also use third-party tools like node-inspector to debug your NodeJS application. If you want to debug a NodeJS application that is hosted on AWS, you can connect to your server running in debug mode from your development machine using the V8 Inspector integration for Node.js.