Simple debugging

VS Code includes a debugger for Node.js out-of-the-box. You can run any JavaScript file with the debugger without any configuration whatsoever.

Simple Debugging

Exercise

Debug the "index.js" file in the "1-simple-debugging" folder and inspect the response.data.results object

Answer

• Open the "index.js" file in the "1-simple-debugging" folder

• Click in the left-hand margin next to line 12 to add a red dot

• Press F5

• Select "Node.js" from the prompt

• The application will run and the breakpoint will be hit

• VS Code will also open the debug panel

• Expand the "response" object on the right-hand side under "variables" and file the "results" object

Note that you can also use the "Debug Console" in the bottom Panel and just enter the name of the command or object you want to run/inspect.

Logpoints

While debugging is normally associated with breakpoints, VS Code has a concept called "Logpoints" . These are breakpoints that simply log out values to the Debug Console. This is useful for when you want to simply inspect a value, but you don't want to have the whole application halt. It's a nice substitute for console.log.

Exercise

Add a log point to the application to log the value of response.data.results to the Debug Console. Run the app and view the log.

Answer

• Right-click the left-hand gutter next to line 12 and select "Add Logpoint"

• Enter Response object is: {response.data.results} and press Enter

If you want an expression evaluated, you must wrap it in {}

• Press F5 to run the "index.js" file with VS Code

• View the Logpoint output in the Debug Console

Note that if your Logpoint is not being logged out, it may be because you have a syntax error. If you have double-checked and it is still not being loaded, reload the VS Code window by opening the Command Palette (Cmd/Ctrl + Shift + P) and selecting "Reload Window".