Debugging

Server debugging

To run your server in debug mode, simply open the run.py file in the root of the repository and start your debugger according to the IDE or editor you’re using:

  • VS Code: Open run.py and click the dropdown of the Play button on the top right of the editor, then select Python Debugger: Debug Python File.

  • PyCharm: Open run.py, right-click on the file and select Debug 'run'. If run is already selected on the top right of the IDE, to the left of the Play button, you can also directly click on the Bug icon, which is on the right hand side of the Play button.

Once the run.py file is running in debug mode, you can set breakpoints in your Python files where code execution will pause.

Office.js add-in debugging

If you need to debug errors with Office.js add-ins, you need to open the developer tools of the browser engine that’s being used. Depending on the platform, the process is different:

  • Desktop Excel on Windows: to open the DevTools, right-click on the task pane and select Inspect.

  • Desktop Excel on macOS: to open Web Inspector, you’ll need to run the following command in a Terminal once:

    defaults write com.microsoft.Excel OfficeWebAddinDeveloperExtras -bool true

    Then, after restarting Excel, right-click on the task pane and select Inspect Element.

    Note

    After running this command, you might see an empty browser window when using other add-ins. To get rid of this, you would need to disable debugging again by running the same command in the Terminal with false instead of true.

  • Excel on the web: open the developer tools of the browser you’re using. For example, in Chrome you can type F12.

Once you have the developer tools showing up, you usually want to look at the following tabs:

  • Console: Here, you’ll find any errors printed. If you use Excel on the web, you’ll see a lot of error messages and warnings that are unrelated to the add-in though, so you’ll need to watch out for relevant messages within the noise.

  • Network: Here, you’ll see if the browser has an issue with loading a specific file. You’ll also be able to double-check the URL of the server and you are able to click on a file to see the content and its headers. Note, however, that you will need to have the Network tab open before making any requests (i.e., reload the add-in, click a button, or run a custom function).