Source code for silx.testutils

# coding: utf-8
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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)