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Diffstat (limited to 'silx/utils/testutils.py')
-rw-r--r-- | silx/utils/testutils.py | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/silx/utils/testutils.py b/silx/utils/testutils.py new file mode 100644 index 0000000..82c2ce3 --- /dev/null +++ b/silx/utils/testutils.py @@ -0,0 +1,281 @@ +# coding: utf-8 +# /*########################################################################## +# +# Copyright (c) 2016-2017 European Synchrotron Radiation Facility +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# +# ###########################################################################*/ +"""Utilities for writing 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. +""" + +__authors__ = ["T. Vincent"] +__license__ = "MIT" +__date__ = "26/01/2018" + + +import contextlib +import functools +import logging +import sys +import unittest + +_logger = logging.getLogger(__name__) + + +if sys.hexversion >= 0x030400F0: # Python >= 3.4 + class ParametricTestCase(unittest.TestCase): + pass +else: + 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 + 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 + + +def parameterize(test_case_class, *args, **kwargs): + """Create a suite containing all tests taken from the given + subclass, passing them the parameters. + + .. code-block:: python + + class TestParameterizedCase(unittest.TestCase): + def __init__(self, methodName='runTest', foo=None): + unittest.TestCase.__init__(self, methodName) + self.foo = foo + + def suite(): + testSuite = unittest.TestSuite() + testSuite.addTest(parameterize(TestParameterizedCase, foo=10)) + testSuite.addTest(parameterize(TestParameterizedCase, foo=50)) + return testSuite + """ + test_loader = unittest.TestLoader() + test_names = test_loader.getTestCaseNames(test_case_class) + suite = unittest.TestSuite() + for name in test_names: + suite.addTest(test_case_class(name, *args, **kwargs)) + return suite + + +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 + # ensure no log message is ignored + self.entry_level = self.logger.level * 1 + self.logger.setLevel(logging.DEBUG) + + def __exit__(self, exc_type, exc_value, traceback): + """Context (i.e., with) support""" + self.logger.removeHandler(self) + self.logger.propagate = True + self.logger.setLevel(self.entry_level) + + 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)) + + def emit(self, record): + """Override :meth:`logging.Handler.emit`""" + self.records.append(record) + + +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 + + +# Simulate missing library context +class EnsureImportError(object): + """This context manager allows to simulate the unavailability + of a library, even if it is actually available. It ensures that + an ImportError is raised if the code inside the context tries to + import the module. + + It can be used to test that a correct fallback library is used, + or that the expected error code is returned. + + Trivial example:: + + from silx.utils.testutils import EnsureImportError + + with EnsureImportError("h5py"): + try: + import h5py + except ImportError: + print("Good") + + .. note:: + + This context manager does not remove the library from the namespace, + if it is already imported. It only ensures that any attempt to import + it again will cause an ImportError to be raised. + """ + def __init__(self, name): + """ + + :param str name: Name of module to be hidden (e.g. "h5py") + """ + self.module_name = name + + def __enter__(self): + """Simulate failed import by setting sys.modules[name]=None""" + if self.module_name not in sys.modules: + self._delete_on_exit = True + self._backup = None + else: + self._delete_on_exit = False + self._backup = sys.modules[self.module_name] + sys.modules[self.module_name] = None + + def __exit__(self, exc_type, exc_val, exc_tb): + """Restore previous state""" + if self._delete_on_exit: + del sys.modules[self.module_name] + else: + sys.modules[self.module_name] = self._backup |