# coding: utf-8
# /*##########################################################################
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# Copyright (c) 2016 European Synchrotron Radiation Facility
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"""Utilities for writting tests.
- :class:`ParametricTestCase` provides a :meth:`TestCase.subTest` replacement
for Python < 3.4
- :class:`TestLogging` with context or the :func:`test_logging` decorator
enables testing the number of logging messages of different levels.
- :func:`temp_dir` provides a with context to create/delete a temporary
directory.
"""
__authors__ = ["T. Vincent"]
__license__ = "MIT"
__date__ = "21/06/2016"
import contextlib
import functools
import logging
import shutil
import sys
import tempfile
import unittest
# Parametric Test Base Class ##################################################
if sys.hexversion >= 0x030400F0: # Python >= 3.4
class ParametricTestCase(unittest.TestCase):
pass
else:
[docs] class ParametricTestCase(unittest.TestCase):
"""TestCase with subTest support for Python < 3.4.
Add subTest method to support parametric tests.
API is the same, but behavior differs:
If a subTest fails, the following ones are not run.
"""
_subtest_msg = None # Class attribute to provide a default value
@contextlib.contextmanager
[docs] def subTest(self, msg=None, **params):
"""Use as unittest.TestCase.subTest method in Python >= 3.4."""
# Format arguments as: '[msg] (key=value, ...)'
param_str = ', '.join(['%s=%s' % (k, v) for k, v in params.items()])
self._subtest_msg = '[%s] (%s)' % (msg or '', param_str)
yield
self._subtest_msg = None
def shortDescription(self):
short_desc = super(ParametricTestCase, self).shortDescription()
if self._subtest_msg is not None:
# Append subTest message to shortDescription
short_desc = ' '.join(
[msg for msg in (short_desc, self._subtest_msg) if msg])
return short_desc if short_desc else None
# Test logging messages #######################################################
[docs]class TestLogging(logging.Handler):
"""Context checking the number of logging messages from a specified Logger.
It disables propagation of logging message while running.
This is meant to be used as a with statement, for example:
>>> with TestLogging(logger, error=2, warning=0):
>>> pass # Run tests here expecting 2 ERROR and no WARNING from logger
...
:param logger: Name or instance of the logger to test.
(Default: root logger)
:type logger: str or :class:`logging.Logger`
:param int critical: Expected number of CRITICAL messages.
Default: Do not check.
:param int error: Expected number of ERROR messages.
Default: Do not check.
:param int warning: Expected number of WARNING messages.
Default: Do not check.
:param int info: Expected number of INFO messages.
Default: Do not check.
:param int debug: Expected number of DEBUG messages.
Default: Do not check.
:param int notset: Expected number of NOTSET messages.
Default: Do not check.
:raises RuntimeError: If the message counts are the expected ones.
"""
def __init__(self, logger=None, critical=None, error=None,
warning=None, info=None, debug=None, notset=None):
if logger is None:
logger = logging.getLogger()
elif not isinstance(logger, logging.Logger):
logger = logging.getLogger(logger)
self.logger = logger
self.records = []
self.count_by_level = {
logging.CRITICAL: critical,
logging.ERROR: error,
logging.WARNING: warning,
logging.INFO: info,
logging.DEBUG: debug,
logging.NOTSET: notset
}
super(TestLogging, self).__init__()
def __enter__(self):
"""Context (i.e., with) support"""
self.records = [] # Reset recorded LogRecords
self.logger.addHandler(self)
self.logger.propagate = False
def __exit__(self, exc_type, exc_value, traceback):
"""Context (i.e., with) support"""
self.logger.removeHandler(self)
self.logger.propagate = True
for level, expected_count in self.count_by_level.items():
if expected_count is None:
continue
# Number of records for the specified level_str
count = len([r for r in self.records if r.levelno == level])
if count != expected_count: # That's an error
# Resend record logs through logger as they where masked
# to help debug
for record in self.records:
self.logger.handle(record)
raise RuntimeError(
'Expected %d %s logging messages, got %d' % (
expected_count, logging.getLevelName(level), count))
[docs] def emit(self, record):
"""Override :meth:`logging.Handler.emit`"""
self.records.append(record)
[docs]def test_logging(logger=None, critical=None, error=None,
warning=None, info=None, debug=None, notset=None):
"""Decorator checking number of logging messages.
Propagation of logging messages is disabled by this decorator.
In case the expected number of logging messages is not found, it raises
a RuntimeError.
>>> class Test(unittest.TestCase):
... @test_logging('module_logger_name', error=2, warning=0)
... def test(self):
... pass # Test expecting 2 ERROR and 0 WARNING messages
:param logger: Name or instance of the logger to test.
(Default: root logger)
:type logger: str or :class:`logging.Logger`
:param int critical: Expected number of CRITICAL messages.
Default: Do not check.
:param int error: Expected number of ERROR messages.
Default: Do not check.
:param int warning: Expected number of WARNING messages.
Default: Do not check.
:param int info: Expected number of INFO messages.
Default: Do not check.
:param int debug: Expected number of DEBUG messages.
Default: Do not check.
:param int notset: Expected number of NOTSET messages.
Default: Do not check.
"""
def decorator(func):
test_context = TestLogging(logger, critical, error,
warning, info, debug, notset)
@functools.wraps(func)
def wrapper(*args, **kwargs):
with test_context:
result = func(*args, **kwargs)
return result
return wrapper
return decorator
# Temporary directory context #################################################
@contextlib.contextmanager
[docs]def temp_dir():
"""with context providing a temporary directory.
>>> import os.path
>>> with temp_dir() as tmp:
... print(os.path.isdir(tmp)) # Use tmp directory
"""
tmp_dir = tempfile.mkdtemp()
try:
yield tmp_dir
finally:
shutil.rmtree(tmp_dir)