Debugging a Node.js application involves several steps using various tools and techniques that are readily available. The following are the main ways to debug a Node.js application:
1. Console.log(): One of the most basic methods of debugging is to use the console.log() method. By writing console.log() in your code, usually inside a function, you can check if your function is working properly and view the values of vars and objects.
1. Node Inspector: A powerful tool for debugging Node.js applications is Node Inspector. To use this tool, install it through npm, then use it to debug your application. Node Inspector is a debugger interface for Node.js applications that uses the Blink Developer Tools (formerly WebKit Web Inspector).
Use command on terminal: npm install -g node-inspector
1. Visual Studio Code (VS Code): VS Code is a source-code editor developed by Microsoft for Windows, Linux and macOS, and it is widely used for Node.js development. It also has an integrated debugging tool that is highly versatile.
1. Node.js Built-in Debugger: Node.js comes with a built-in debugger.
To start debugging your Node application, use the following command:
1. Utilizing the —inspect flag in Node.js 6.3+: Starting Node.js with —inspect will start the V8 inspector and allows tools like Chrome DevTools and others to connect to Node.js instance.
node —inspect1. Utilize async\_hooks API (available in Node.js 8.0+): Helps to debug asynchronous operations, it allows tracking async resources throughout their lifecycle.
Remember, before debugging it’s crucial to understand the flow of your program and its control structures. Step by step execution can be enabled using breakpoints in VS Code or Node inspector.
