import logging
import collections
from .case import _BaseTestCaseContext
_LoggingWatcher = collections.namedtuple("_LoggingWatcher",
["records", "output"])
class _CapturingHandler(logging.Handler):
"""
A logging handler capturing all (raw and formatted) logging output.
"""
def __init__(self):
logging.Handler.__init__(self)
self.watcher = _LoggingWatcher([], [])
def flush(self):
pass
def emit(self, record):
self.watcher.records.append(record)
msg = self.format(record)
self.watcher.output.append(msg)
class _AssertLogsContext(_BaseTestCaseContext):
"""A context manager used to implement TestCase.assertLogs()."""
LOGGING_FORMAT = "%(levelname)s:%(name)s:%(message)s"
def __init__(self, test_case, logger_name, level):
_BaseTestCaseContext.__init__(self, test_case)
self.logger_name = logger_name
if level:
self.level = logging._nameToLevel.get(level, level)
else:
self.level = logging.INFO
self.msg = None
def __enter__(self):
if isinstance(self.logger_name, logging.Logger):
logger = self.logger = self.logger_name
else:
logger = self.logger = logging.getLogger(self.logger_name)
formatter = logging.Formatter(self.LOGGING_FORMAT)
handler = _CapturingHandler()
handler.setFormatter(formatter)
self.watcher = handler.watcher
self.old_handlers = logger.handlers[:]
self.old_level = logger.level
self.old_propagate = logger.propagate
logger.handlers = [handler]
logger.setLevel(self.level)
logger.propagate = False
return handler.watcher
def __exit__(self, exc_type, exc_value, tb):
self.logger.handlers = self.old_handlers
self.logger.propagate = self.old_propagate
self.logger.setLevel(self.old_level)
if exc_type is not None:
# let unexpected exceptions pass through
return False
if len(self.watcher.records) == 0:
self._raiseFailure(
"no logs of level {} or higher triggered on {}"
.format(logging.getLevelName(self.level), self.logger.name))
