xml report file is empty

[petobens]

Using the following command:

pytest --cov-report xml --cov-report html --cov=. tests/

the html coverage report is generated under htmlcov/ but the coverage.xml file is empty.
Can you reproduce this behaviour? I'm using:

pytest (3.3.2)
pytest-cov (2.5.1)
coverage (4.4.2)

Thanks in advance!

[ionelmc]

It's not clear what is the problem. Are you getting hits in the html report but none in the xml one?

[petobens]

Hi @ionelmc thanks for the quick reply. What I meant was that the file coverage.xml is indeed generated but without content (i.e it's a just a blank file). On the other hand, all the files under htmlcov do have content (i.e are not empty/blank). I hope it's a bit clearer now.

[ionelmc]

Yes but isn't that the expected behavior? Html report just copies the files and marks what code wasn't run. Xml report only reports covered modules.

[petobens]

@ionelmc I'm probably not following you. Sorry about that.

With

pytest --tb=short -q --cov-report term-missing --cov=. tests/ --cov-config tests/coveragerc

I get

---------- coverage: platform darwin, python 3.6.4-final-0 -----------
Name                     Stmts   Miss  Cover   Missing
------------------------------------------------------
__init__.py                  1      1     0%   1
_version.py                  1      1     0%   1
config.py                   13      0   100%
data.py                    203      2    99%   135-136
dino_bot.py                 20      0   100%
drex.py                     82     82     0%   2-179
preprocessing.py           138      0   100%
products_subqueries.py      36      7    81%   75-77, 81-85
recommender.py             242      4    98%   458-459, 479-480
results_output.py          139      0   100%
ruby_api.py                 84      0   100%
utils.py                    78      0   100%
------------------------------------------------------
TOTAL                     1037     97    91%

If I now replace the --cov-report to use xml instead of term-missing a blank coverage.xml file is generated. Is this the expected behaviour?

PS: coveragerc file is just:

[run]
omit = tests/*,notebooks/*

[ionelmc]

Now I see. It shouldn't be empty. Is it 0 bytes? Please add more details. A reproducer would be even better.

[petobens]

It is indeed 0 bytes. I''ll try to write up a minimal reproducible example and report back. Thanks

[petobens]

I found a way of reproducing it:
Inside ~/Desktop/testing/ i have two files
i) foo.py with

import time
import logging

from functools import wraps

logger = logging.getLogger(__name__)


def f(x):
    if x > 1:
        return x**2
    else:
        raise ValueError


def timeit(logger):
    """Record the time it takes to run a function."""

    def decorator(func):

        @wraps(func)
        def wrapper(*args, **kwargs):
            start = time.time()
            result = func(*args, **kwargs)
            duration = time.time() - start
            logger.info(f"{func.__name__} took: {duration:.4f} sec")
            return result

        return wrapper

    return decorator

and ii) tests/test_foo.py with

import os
import sys
import time

from unittest.mock import MagicMock

sys.path.append(
    os.path.abspath(os.path.join(os.path.dirname(__file__), os.path.pardir))
)

import foo
import pytest


class TestFoo:

    @pytest.fixture()
    def logger(self, monkeypatch):
        monkeypatch.setattr('foo.logger', MagicMock())
        return foo.logger

    def test_f(self):
        assert 4 == foo.f(2)

    def test_timeit(self, logger):
        start = 1000000000
        duration = 100
        time.time = MagicMock(side_effect=(start, start + duration))

        @foo.timeit(logger)
        def x():
            return

        x()
        logger.info.assert_called_once_with(f'x took: {duration}.0000 sec')

If I now run pytest --tb=short -q --cov-report xml --cov=. tests/ then the coverage.xml file is empty. However if you comment/remove the test_timeit method then everything works as expected. Please let me know if you can reproduce this ( I might be testing the timeit decorator wrongly).

[ionelmc]

You might be causing some weird error in coverage as you do not undo the time.time monkeypatch?

[petobens]

You are correct! The following does the trick

        time_mock = MagicMock(side_effect=(start, start + duration))
        monkeypatch.setattr('time.time', time_mock)

Thank you!!