Method assertLogs

Lib/unittest/case.py:852–876

Fail unless a log message of level *level* or higher is emitted on *logger_name* or its children. If omitted, *level* defaults to INFO and *logger* defaults to the root logger. This method must be used as a context manager, and will yield a recording object with two

(self, logger=None, level=None, formatter=None)

        return context.handle('_assertNotWarns', args, kwargs)

    def assertLogs(self, logger=None, level=None, formatter=None):
        """Fail unless a log message of level *level* or higher is emitted
        on *logger_name* or its children.  If omitted, *level* defaults to
        INFO and *logger* defaults to the root logger.

        This method must be used as a context manager, and will yield
        a recording object with two attributes: `output` and `records`.
        At the end of the context manager, the `output` attribute will
        be a list of the matching formatted log messages and the
        `records` attribute will be a list of the corresponding LogRecord
        objects.

        Optionally supply `formatter` to control how messages are formatted.

        Example::

            with self.assertLogs('foo', level='INFO') as cm:
                logging.getLogger('foo').info('first message')
                logging.getLogger('foo.bar').error('second message')
            self.assertEqual(cm.output, ['INFO:foo:first message',
                                         'ERROR:foo.bar:second message'])
        """
        # Lazy import to avoid importing logging if it is not needed.
        from ._log import _AssertLogsContext
        return _AssertLogsContext(self, logger, level, no_logs=False, formatter=formatter)

    def assertNoLogs(self, logger=None, level=None):
        """ Fail unless no log messages of level *level* or higher are emitted