Check test coverage

[ev-br]

Lots of stuff is untested hence broken.

[ev-br]

Checked locally, the line coverage is pretty decent actually. Logic coverage is not the same, and it'd be great to check that tests adequately cover various aspects of the behavior.

[Sheila-nk]

I think we can eventually set up Codecov to track code coverage.
It is easy to set up and free for open-source projects. Here is the quick start guide if you want to check it out.

[ev-br]

May want to look into the coverage of the plugin specifically, and various ways to orchestrate the run.