Difficulty in Configuring Loguru to Honor --log-cli-level=INFO in Pytest (hashtag1062)

[vikramsubramanian]

hashtaghashtaghashtag Environment

• Python Version: 3.9
• Loguru Version: 0.7.2
• Pytest Version: 7.4.4

hashtaghashtaghashtag Description I am encountering an issue with configuring Loguru to work in tandem with Pytest's --log-cli-level flag. Recently I start to switch logging from python native logging to Loguru. It's indeed simple and coll. However, I found when it goes to pytest, it became somehow confusing. My goal is to run Pytest with the flag --log-cli-level=INFO or --log-level=INFO and ensure that DEBUG level messages are not shown in the test output. However, despite various attempts and configurations, DEBUG messages are still being displayed.

hashtaghashtaghashtag Steps to Reproduce

1. Write a test function that includes loguru logger messages at various levels, including DEBUG.
2. Run Pytest with the command: python -m pytest -s tests --log-cli-level=INFO.
3. Observe that DEBUG messages are still appearing in the output.

hashtaghashtaghashtag What I've Tried

• I've read through related GitHub issues (GHhashtag59 and GHhashtag474) and the official loguru documentation (

• I've tried using a caplog fixture to integrate loguru logger with pytest's logging mechanism as shown below:

  
  def caplog(caplog: LogCaptureFixture):
      handler_id = logger.add(
          caplog.handler,
          format="{message}",
          level=0,
          filter=lambda record: record["level"].no >= caplog.handler.level,
          enqueue=False,
      )
      yield caplog
      logger.remove(handler_id)

• I've also tried adding a reportlog fixture to handle log messages:

  
  def reportlog(pytestconfig):
      logging_plugin = pytestconfig.pluginmanager.getplugin("logging-plugin")
      handler_id = logger.add(logging_plugin.report_handler, format="{message}")
      yield
      logger.remove(handler_id)

• I've also try pytest-loguru, but also not getting what I want.

hashtaghashtaghashtag Expected Behavior I would expect that running Pytest with --log-cli-level=INFO would result in DEBUG level messages being filtered out from the test output.

hashtaghashtaghashtag Actual Behavior DEBUG level messages are still being displayed in the test output.

hashtaghashtaghashtag Request Could you please provide guidance or a solution on how to configure loguru to respect the --log-cli-level=INFO flag in Pytest? Any assistance or insights into this issue would be greatly appreciated.

Thank you for your time and help. )

[mayil-ai[bot]]

Possible Solution

• To ensure that DEBUG level messages are not displayed when --log-cli-level=INFO is used, you need to configure the Loguru logger to respect the Pytest logging level.
• Modify the configure_logger function to set the Loguru logger level based on the Pytest --log-cli-level flag.
• Use the caplog fixture to capture the logging output and set the appropriate level.

Here is a solution to configure Loguru correctly with Pytest:

# Pytest logging integration
import pytest
from loguru import logger

@pytest.fixture
def caplog(caplog):
    class PropagateHandler(logging.Handler):
        def emit(self, record):
            logging.getLogger(record.name).handle(record)

    handler_id = logger.add(PropagateHandler(), format="{message}")
    logger.level("DEBUG", no=10, color="<blue>", icon="🐞")
    logger.level("INFO", no=20, color="<green>", icon="ℹ️")
    logger.level("WARNING", no=30, color="<yellow>", icon="⚠️")
    logger.level("ERROR", no=40, color="<red>", icon="❌")
    logger.level("CRITICAL", no=50, color="<RED><bold>", icon="☠️")

    caplog.set_level(logging.INFO)
    yield caplog
    logger.remove(handler_id)

• Add the PropagateHandler class inside the caplog fixture to propagate logs from Loguru to the standard logging module.
• Use logger.add to add the PropagateHandler to Loguru's handlers.
• Define custom levels for Loguru if needed, ensuring that the no (number) matches the standard logging levels.
• Set the Pytest caplog level to logging.INFO or retrieve the level from the Pytest configuration if you want to dynamically set it based on the --log-cli-level flag.
• After yielding caplog for the test, remove the handler from Loguru to clean up.

Code snippets to check

loguru → _logger.py

This snippet contains the 'add' method which is used to configure Loguru sinks, including setting the level of logging. It is relevant to the issue as the user is having trouble with setting the correct log level when using Pytest. https://github.com/Mayil-AI/loguru/blob/871de74acb2382fb3982d3fb8e224e4a82de9073/loguru/_logger.py#L253-L2094 This snippet includes code that checks the log level and determines whether to proceed with logging. It is relevant because it may contain logic that needs to be adjusted to respect the '--log-cli-level' flag from Pytest. https://github.com/Mayil-AI/loguru/blob/871de74acb2382fb3982d3fb8e224e4a82de9073/loguru/_logger.py#L1906-L2020 This snippet defines the logging methods for different levels, including 'DEBUG' and 'INFO'. It is relevant because the issue involves these specific log levels and their behavior when running tests with Pytest. https://github.com/Mayil-AI/loguru/blob/871de74acb2382fb3982d3fb8e224e4a82de9073/loguru/_logger.py#L2033-L2086