Now, with great power comes great responsibility. For now, we are committing to the master branch, which is the default one for installation, so we probably don't want to add some unreliable code there. So, let's adhere to the following, rather simple, practice—we should never push code directly to the master branch. Instead, we should work on a separate development branch, push it to GitHub, and then—once we're satisfied with results—merge the branch into the master. For that, GitHub even supports code review and discussions. Let's switch to a development branch now:

git checkout -b tests

As you may notice, VS Code will mark the current branch in the lower-left corner of the window. In fact, you can click on it and switch to a different branch or even create a new one manually. Next comes testing the code and checking how it works.