The gutters are based on coverage output file, for example the coverage.xml file.
Configure a coverage plugin, run your tests with the coverage plugin and let Coverage-gutters watch.
An example for a Django:
$ coverage python manage.py test
$ coverage xml
A generated coverage.xml has now been written in your project's root and your VSCode Coverage-Gutters should now be visible.
I try to use Coverage-Gutters. But the documentation is quite complicated and I kinda don't understand on how can it be used. I already installed the extension but I tried a number of things and it seems to be not working. Is there anyone know how to use it?
Coverage-Gutter on Visual Studio Code