How to debug Angular in Visual Studio Code?

How to Debug Angular in Visual Studio Code?

As a developer, debugging is an essential part of the development process. In this article, we will explore how to debug Angular applications in Visual Studio Code (VS Code), a lightweight and powerful code editor. Visual Studio Code is a popular choice among developers due to its ease of use, flexibility, and wide range of extensions.

Getting Started with Debugging in Visual Studio Code

Before we dive into the world of debugging, make sure you have Visual Studio Code installed on your machine. If you haven’t, you can download it from the official Visual Studio Code website. Once installed, follow these steps to set up the debugger:

1. Create a new folder for your project and initialize a new Angular project using the Angular CLI.
2. Open your project in Visual Studio Code by navigating to the folder and opening it with VS Code.
3. Install the Debugger for Chrome by running the following command in your terminal: npm install --global chrome-debug. This extension allows you to debug Chrome directly from Visual Studio Code.
4. Install the Angular Language Server by running the following command in your terminal: npm install --save-dev@angular/language-server`. This extension provides Intellisense, debugging, and code analysis for Angular.

Debugging Your Angular Application

Now that you have set up the environment, it’s time to start debugging your application. Here are the steps to follow:

Launch the Debugger

1. Open the Command Palette in Visual Studio Code by pressing Ctrl + Shift + P (Windows, Linux) or Cmd + Shift + P (macOS).
2. Type "Angular: Open in Chrome" in the Command Palette search bar and select the Angular: Open in Chrome command.
3. Select the browser instance you want to debug from the dropdown menu.

Set Breakpoints

1. Add breakpoints in your code by clicking on the line number in the gutter area of the code editor. The line will turn blue, indicating it’s a breakpoint.
2. Create a new file to debug by right-clicking on the Project Explorer and selecting New File or by using the keyboard shortcut Ctrl + N (Windows, Linux) or Cmd + N (macOS).
3. Create a simple Angular component in the new file, for example: app.component.html.
4. Add a debugger statement to the component, for example: debugger; or debugger();.

Start Debugging

1. Launch the debugger by clicking the Run button in the top-right corner of the Visual Studio Code window or by using the keyboard shortcut F5 (Windows, Linux) or Cmd + Enter (macOS).
2. Your browser will launch with your Angular application, and the debugger will pause at the first breakpoint.

Step Through Your Code

1. Step over to the next line by clicking the Step Over button in the debug toolbar or by using the keyboard shortcut F10 (Windows, Linux) or Cmd + . (macOS).
2. Step into a function by clicking the Step Into button in the debug toolbar or by using the keyboard shortcut F11 (Windows, Linux) or Cmd + Shift + . (macOS).
3. Step out of a function by clicking the Step Out button in the debug toolbar or by using the keyboard shortcut Shift + F11 (Windows, Linux) or Cmd + Shift + . (macOS).

Inspect and Debug

1. Inspect variables by hovering over them in the code editor or by using the Variables panel in the Debug View.
2. Set watch expressions by clicking the Watch button in the debug toolbar or by using the keyboard shortcut Ctrl + Shift + W (Windows, Linux) or Cmd + Shift + W (macOS).
3. Use the Debug Console to execute expressions, inspect variables, and debug your application.

Tips and Tricks

• Use the Debug View to quickly switch between different debug contexts.
• Enable the : Forbid Unused lint to prevent unused variables and functions from being added to your code.
• Use the : class height** setting in your angular.json file to adjust the height of the editor.
• Use the : element-select setting in your angular.json file to select the element to debug.

Conclusion

In this article, we have seen how to set up and use the debug debugger in Visual Studio Code for Angular applications. We have covered the basics of debugging, including launching the debugger, setting breakpoints, and stepping through your code. With these tips and tricks, you should be well on your way to becoming a proficient Angular developer and debugger.

Offline Debugging

If you don’t have a local development environment set up or want to debug your application offline, you can use the ng debug command to debug your application.

ng debug

The ng debug command allows you to debug your Angular application without the need for a local development environment. You can debug your application in a Node.js environment or a browser instance. Here are the steps to use the ng debug command:

1. Run the ng debug command in your terminal: ng debug.
2. Select the application you want to debug from the dropdown menu.
3. Set breakpoints in your code as described above.
4. Start debugging your application by clicking the Start Debugging button in the Debug View.

This concludes our article on how to debug Angular in Visual Studio Code. Remember to always keep your code organized, use meaningful variable names, and set clear goals for your debugger to ensure a productive and efficient debugging experience.