How to use logging, pytest fixture and capsys?

Question

I am trying to unit-test some algorithm that uses logging library.

I have a fixture that creates a logger.

In my 1st test case, I do not use

Answer 1

Thanks a lot for your ideas!

Reverse logger, capsys, make logger request the capsys fixture and use capfd do not change anything.

I tried pytest-catchlog plugin and it works fine!

import pytest

import logging

@pytest.fixture()
def logger():

    logger = logging.getLogger('Some.Logger')
    logger.setLevel(logging.INFO)

    return logger

def test_logger_with_fixture(logger, caplog):

    logger.info('Bouyaka!')

    assert 'Bouyaka!' in caplog.text

    # passes!

In my original tests, I logged to stdout and stderr and captured them. This is an even better solution, as I do not need this tweak to check that my logs work fine.

Well, now I just need to rework all my tests to use caplog, but this is my own business ;)

The only thing left, now that I have a better solution, is to understand what is wrong in my original test case def test_logger_with_fixture(logger, capsys).