Add tests in test_painter.py to Pytest marker unit

[felix-seifert]

I discovered that we have some more unit tests. They should receive the Pytest marker unit to be automatically executed in our CI workflow.

[felix-seifert]

@csgoh Can you please have a look at the test failures?

The test src/tests/test_painter.py::TestPainter::test_get_text_dimension2 fails on Ubuntu. The problem seems to be that the text_width is not the expected range. If I run the test on my computer (it is an Ubuntu), everything is fine. Maybe, you have an idea about the dependant library and how to cope with the problem.

[csgoh]

Hi @felix-seifert

Sorry for not responding earlier, as I am still on holiday 😄 I will be back by end of this month.

Regarding the error, I suspect it is a font file issue. I understand the Arial font by default does not come with Linux. Can I suggest we try using SourceHanSerifTC-Bold.otf in the font folder?

CS

[felix-seifert]

Just realised that the test specifies the usage of Arial. 🙈 I fixed the two tests in my last commit to this PR.

I had a closer look at the other tests in the file and I thought we do not rely on Arial anymore. We wanted to ensure that we can generate roadmaps out of the box on every OS. Nevertheless, this test shows that the theme ORANGEPEEL uses Arial. Do we actually say that we except that the standard version works without Arial and the theme is already custom?