How do I debug Node.js applications?

Debugging Node.js applications can be done using various tools and techniques. Here are some common approaches to debug Node.js applications:

console.log

The simplest form of debugging is using console.log statements to print values or log messages at different points in your code. This can help you understand the flow of your program and identify potential issues.

console.log('Value of variable:', someVariable);

Node.js inspector

Node.js comes with a built-in inspector. You can start your script with the -inspect flag and use the Chrome DevTools for debugging. The newer versions of Node.js recommend using the -inspect flag.

node --inspect your-script.js

Then open Chrome and go to chrome://inspect to connect to your Node.js process.

Debugger Statement

Insert the debugger statement in your code where you want to set a breakpoint. When the script runs, it will pause at this point, allowing you to inspect variables and step through the code.

function someFunction() {
  // ...
  debugger;
  // ...
}

Visual Studio Code (VSCode)

If you're using Visual Studio Code, it has excellent built-in support for Node.js debugging. You can set breakpoints, step through code, and inspect variables directly in the editor.

Third-Party Debugging Tools:

There are also third-party debugging tools like ndb, which provides an improved debugging experience with additional features.

npx ndb your-script.js

Remember to install ndb globally if you want to use it without npx.

npm install -g ndb

Choose the method that best fits your workflow and preferences. Using a combination of these tools can provide a comprehensive approach to debugging your Node.js applications.

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