Function test_live_logging_suspends_capture

testing/logging/test_reporting.py:822–867

Test that capture manager is suspended when we emitting messages for live logging. This tests the implementation calls instead of behavior because it is difficult/impossible to do it using ``pytester`` facilities because they do their own capturing. We parametrize the test to also make

(
    has_capture_manager: bool, request: FixtureRequest
)

@pytest.mark.parametrize("has_capture_manager", [True, False])
def test_live_logging_suspends_capture(
    has_capture_manager: bool, request: FixtureRequest
) -> None:
    """Test that capture manager is suspended when we emitting messages for live logging.

    This tests the implementation calls instead of behavior because it is difficult/impossible to do it using
    ``pytester`` facilities because they do their own capturing.

    We parametrize the test to also make sure _LiveLoggingStreamHandler works correctly if no capture manager plugin
    is installed.
    """
    import logging
    import contextlib
    from functools import partial
    from _pytest.logging import _LiveLoggingStreamHandler

    class MockCaptureManager:
        calls = []

        @contextlib.contextmanager
        def global_and_fixture_disabled(self):
            self.calls.append("enter disabled")
            yield
            self.calls.append("exit disabled")

    class DummyTerminal(io.StringIO):
        def section(self, *args, **kwargs):
            pass

    out_file = cast(TerminalReporter, DummyTerminal())
    capture_manager = (
        cast(CaptureManager, MockCaptureManager()) if has_capture_manager else None
    )
    handler = _LiveLoggingStreamHandler(out_file, capture_manager)
    handler.set_when("call")

    logger = logging.getLogger(__name__ + ".test_live_logging_suspends_capture")
    logger.addHandler(handler)
    request.addfinalizer(partial(logger.removeHandler, handler))

    logger.critical("some message")
    if has_capture_manager:
        assert MockCaptureManager.calls == ["enter disabled", "exit disabled"]
    else:
        assert MockCaptureManager.calls == []
    assert cast(io.StringIO, out_file).getvalue() == "\nsome message\n"


def test_collection_live_logging(pytester: Pytester) -> None: