[Python] Coverage Discrepancies in pytest: Code Executed but Not Tracked

I discovered that when I run pytest with coverage, the coverage report shows that the tests do not fully cover the code, even though the tests execute the relevant code.

Full Coverage Command (100% Coverage)


coverage run --source=/root/MyProject/lib_python -m pytest /root/MyProject/tests/lib_python/test_something.py

Partial Coverage Command (50% Coverage)

• cd /root/MyProject; coverage run --source=lib_python -m pytest
• cd /root/MyProject; coverage run --source=lib_python -m pytest /root/MyProject/tests/lib_python/

Using the second command, the coverage report indicates that the lines return a + b and return a - b in lib_python/something.py are not covered.

Context:

• PYTHONPATH: /root/MyProject/lib_python
• My module doesn't have a package name. It is unusual but it's due to legacy reasons.

Code Files:

lib_python/something.py


def add(a, b):
return a + b


def sub(a, b):
return a - b

tests/lib_python/test_something.py


python

from something import add, sub

def test_add():
assert add(1, 2) == 3
assert add(-1, 1) == 0
assert add(0, 0) == 0

def test_sub():
assert sub(2, 1) == 1
assert sub(1, 1) == 0
assert sub(0, 1) == -1


How do I get my coverage command to find and match coverage with the actual file?

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