Test demo: test coverage

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pip install pytest-cover

$ pytest test_with_pytest.py --cov mymath --cov-report html --cov-report term

========================= test session starts ==========================
platform linux -- Python 3.11.2, pytest-7.3.1, pluggy-1.0.0
rootdir: /home/gabor/work/slides/python/examples/testing-demo
plugins: anyio-3.6.2, cov-4.0.0
collected 1 item

test_with_pytest.py .                                            [100%]

---------- coverage: platform linux, python 3.11.2-final-0 -----------
Name        Stmts   Miss  Cover
-------------------------------
mymath.py       4      1    75%
-------------------------------
TOTAL           4      1    75%
Coverage HTML written to dir htmlcov


========================== 1 passed in 0.03s ===========================

Open htmlcov/index.html