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Diffstat (limited to 'python/google/protobuf/internal/_parameterized.py')
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diff --git a/python/google/protobuf/internal/_parameterized.py b/python/google/protobuf/internal/_parameterized.py new file mode 100755 index 00000000..6ed23308 --- /dev/null +++ b/python/google/protobuf/internal/_parameterized.py @@ -0,0 +1,438 @@ +#! /usr/bin/python +# +# Protocol Buffers - Google's data interchange format +# Copyright 2008 Google Inc. All rights reserved. +# https://developers.google.com/protocol-buffers/ +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above +# copyright notice, this list of conditions and the following disclaimer +# in the documentation and/or other materials provided with the +# distribution. +# * Neither the name of Google Inc. nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +"""Adds support for parameterized tests to Python's unittest TestCase class. + +A parameterized test is a method in a test case that is invoked with different +argument tuples. + +A simple example: + + class AdditionExample(parameterized.ParameterizedTestCase): + @parameterized.Parameters( + (1, 2, 3), + (4, 5, 9), + (1, 1, 3)) + def testAddition(self, op1, op2, result): + self.assertEquals(result, op1 + op2) + + +Each invocation is a separate test case and properly isolated just +like a normal test method, with its own setUp/tearDown cycle. In the +example above, there are three separate testcases, one of which will +fail due to an assertion error (1 + 1 != 3). + +Parameters for invididual test cases can be tuples (with positional parameters) +or dictionaries (with named parameters): + + class AdditionExample(parameterized.ParameterizedTestCase): + @parameterized.Parameters( + {'op1': 1, 'op2': 2, 'result': 3}, + {'op1': 4, 'op2': 5, 'result': 9}, + ) + def testAddition(self, op1, op2, result): + self.assertEquals(result, op1 + op2) + +If a parameterized test fails, the error message will show the +original test name (which is modified internally) and the arguments +for the specific invocation, which are part of the string returned by +the shortDescription() method on test cases. + +The id method of the test, used internally by the unittest framework, +is also modified to show the arguments. To make sure that test names +stay the same across several invocations, object representations like + + >>> class Foo(object): + ... pass + >>> repr(Foo()) + '<__main__.Foo object at 0x23d8610>' + +are turned into '<__main__.Foo>'. For even more descriptive names, +especially in test logs, you can use the NamedParameters decorator. In +this case, only tuples are supported, and the first parameters has to +be a string (or an object that returns an apt name when converted via +str()): + + class NamedExample(parameterized.ParameterizedTestCase): + @parameterized.NamedParameters( + ('Normal', 'aa', 'aaa', True), + ('EmptyPrefix', '', 'abc', True), + ('BothEmpty', '', '', True)) + def testStartsWith(self, prefix, string, result): + self.assertEquals(result, strings.startswith(prefix)) + +Named tests also have the benefit that they can be run individually +from the command line: + + $ testmodule.py NamedExample.testStartsWithNormal + . + -------------------------------------------------------------------- + Ran 1 test in 0.000s + + OK + +Parameterized Classes +===================== +If invocation arguments are shared across test methods in a single +ParameterizedTestCase class, instead of decorating all test methods +individually, the class itself can be decorated: + + @parameterized.Parameters( + (1, 2, 3) + (4, 5, 9)) + class ArithmeticTest(parameterized.ParameterizedTestCase): + def testAdd(self, arg1, arg2, result): + self.assertEqual(arg1 + arg2, result) + + def testSubtract(self, arg2, arg2, result): + self.assertEqual(result - arg1, arg2) + +Inputs from Iterables +===================== +If parameters should be shared across several test cases, or are dynamically +created from other sources, a single non-tuple iterable can be passed into +the decorator. This iterable will be used to obtain the test cases: + + class AdditionExample(parameterized.ParameterizedTestCase): + @parameterized.Parameters( + c.op1, c.op2, c.result for c in testcases + ) + def testAddition(self, op1, op2, result): + self.assertEquals(result, op1 + op2) + + +Single-Argument Test Methods +============================ +If a test method takes only one argument, the single argument does not need to +be wrapped into a tuple: + + class NegativeNumberExample(parameterized.ParameterizedTestCase): + @parameterized.Parameters( + -1, -3, -4, -5 + ) + def testIsNegative(self, arg): + self.assertTrue(IsNegative(arg)) +""" + +__author__ = 'tmarek@google.com (Torsten Marek)' + +import collections +import functools +import re +import types +import unittest +import uuid + +from google.apputils import basetest + +ADDR_RE = re.compile(r'\<([a-zA-Z0-9_\-\.]+) object at 0x[a-fA-F0-9]+\>') +_SEPARATOR = uuid.uuid1().hex +_FIRST_ARG = object() +_ARGUMENT_REPR = object() + + +def _CleanRepr(obj): + return ADDR_RE.sub(r'<\1>', repr(obj)) + + +# Helper function formerly from the unittest module, removed from it in +# Python 2.7. +def _StrClass(cls): + return '%s.%s' % (cls.__module__, cls.__name__) + + +def _NonStringIterable(obj): + return (isinstance(obj, collections.Iterable) and not + isinstance(obj, basestring)) + + +def _FormatParameterList(testcase_params): + if isinstance(testcase_params, collections.Mapping): + return ', '.join('%s=%s' % (argname, _CleanRepr(value)) + for argname, value in testcase_params.iteritems()) + elif _NonStringIterable(testcase_params): + return ', '.join(map(_CleanRepr, testcase_params)) + else: + return _FormatParameterList((testcase_params,)) + + +class _ParameterizedTestIter(object): + """Callable and iterable class for producing new test cases.""" + + def __init__(self, test_method, testcases, naming_type): + """Returns concrete test functions for a test and a list of parameters. + + The naming_type is used to determine the name of the concrete + functions as reported by the unittest framework. If naming_type is + _FIRST_ARG, the testcases must be tuples, and the first element must + have a string representation that is a valid Python identifier. + + Args: + test_method: The decorated test method. + testcases: (list of tuple/dict) A list of parameter + tuples/dicts for individual test invocations. + naming_type: The test naming type, either _NAMED or _ARGUMENT_REPR. + """ + self._test_method = test_method + self.testcases = testcases + self._naming_type = naming_type + + def __call__(self, *args, **kwargs): + raise RuntimeError('You appear to be running a parameterized test case ' + 'without having inherited from parameterized.' + 'ParameterizedTestCase. This is bad because none of ' + 'your test cases are actually being run.') + + def __iter__(self): + test_method = self._test_method + naming_type = self._naming_type + + def MakeBoundParamTest(testcase_params): + @functools.wraps(test_method) + def BoundParamTest(self): + if isinstance(testcase_params, collections.Mapping): + test_method(self, **testcase_params) + elif _NonStringIterable(testcase_params): + test_method(self, *testcase_params) + else: + test_method(self, testcase_params) + + if naming_type is _FIRST_ARG: + # Signal the metaclass that the name of the test function is unique + # and descriptive. + BoundParamTest.__x_use_name__ = True + BoundParamTest.__name__ += str(testcase_params[0]) + testcase_params = testcase_params[1:] + elif naming_type is _ARGUMENT_REPR: + # __x_extra_id__ is used to pass naming information to the __new__ + # method of TestGeneratorMetaclass. + # The metaclass will make sure to create a unique, but nondescriptive + # name for this test. + BoundParamTest.__x_extra_id__ = '(%s)' % ( + _FormatParameterList(testcase_params),) + else: + raise RuntimeError('%s is not a valid naming type.' % (naming_type,)) + + BoundParamTest.__doc__ = '%s(%s)' % ( + BoundParamTest.__name__, _FormatParameterList(testcase_params)) + if test_method.__doc__: + BoundParamTest.__doc__ += '\n%s' % (test_method.__doc__,) + return BoundParamTest + return (MakeBoundParamTest(c) for c in self.testcases) + + +def _IsSingletonList(testcases): + """True iff testcases contains only a single non-tuple element.""" + return len(testcases) == 1 and not isinstance(testcases[0], tuple) + + +def _ModifyClass(class_object, testcases, naming_type): + assert not getattr(class_object, '_id_suffix', None), ( + 'Cannot add parameters to %s,' + ' which already has parameterized methods.' % (class_object,)) + class_object._id_suffix = id_suffix = {} + for name, obj in class_object.__dict__.items(): + if (name.startswith(unittest.TestLoader.testMethodPrefix) + and isinstance(obj, types.FunctionType)): + delattr(class_object, name) + methods = {} + _UpdateClassDictForParamTestCase( + methods, id_suffix, name, + _ParameterizedTestIter(obj, testcases, naming_type)) + for name, meth in methods.iteritems(): + setattr(class_object, name, meth) + + +def _ParameterDecorator(naming_type, testcases): + """Implementation of the parameterization decorators. + + Args: + naming_type: The naming type. + testcases: Testcase parameters. + + Returns: + A function for modifying the decorated object. + """ + def _Apply(obj): + if isinstance(obj, type): + _ModifyClass( + obj, + list(testcases) if not isinstance(testcases, collections.Sequence) + else testcases, + naming_type) + return obj + else: + return _ParameterizedTestIter(obj, testcases, naming_type) + + if _IsSingletonList(testcases): + assert _NonStringIterable(testcases[0]), ( + 'Single parameter argument must be a non-string iterable') + testcases = testcases[0] + + return _Apply + + +def Parameters(*testcases): + """A decorator for creating parameterized tests. + + See the module docstring for a usage example. + Args: + *testcases: Parameters for the decorated method, either a single + iterable, or a list of tuples/dicts/objects (for tests + with only one argument). + + Returns: + A test generator to be handled by TestGeneratorMetaclass. + """ + return _ParameterDecorator(_ARGUMENT_REPR, testcases) + + +def NamedParameters(*testcases): + """A decorator for creating parameterized tests. + + See the module docstring for a usage example. The first element of + each parameter tuple should be a string and will be appended to the + name of the test method. + + Args: + *testcases: Parameters for the decorated method, either a single + iterable, or a list of tuples. + + Returns: + A test generator to be handled by TestGeneratorMetaclass. + """ + return _ParameterDecorator(_FIRST_ARG, testcases) + + +class TestGeneratorMetaclass(type): + """Metaclass for test cases with test generators. + + A test generator is an iterable in a testcase that produces callables. These + callables must be single-argument methods. These methods are injected into + the class namespace and the original iterable is removed. If the name of the + iterable conforms to the test pattern, the injected methods will be picked + up as tests by the unittest framework. + + In general, it is supposed to be used in conjuction with the + Parameters decorator. + """ + + def __new__(mcs, class_name, bases, dct): + dct['_id_suffix'] = id_suffix = {} + for name, obj in dct.items(): + if (name.startswith(unittest.TestLoader.testMethodPrefix) and + _NonStringIterable(obj)): + iterator = iter(obj) + dct.pop(name) + _UpdateClassDictForParamTestCase(dct, id_suffix, name, iterator) + + return type.__new__(mcs, class_name, bases, dct) + + +def _UpdateClassDictForParamTestCase(dct, id_suffix, name, iterator): + """Adds individual test cases to a dictionary. + + Args: + dct: The target dictionary. + id_suffix: The dictionary for mapping names to test IDs. + name: The original name of the test case. + iterator: The iterator generating the individual test cases. + """ + for idx, func in enumerate(iterator): + assert callable(func), 'Test generators must yield callables, got %r' % ( + func,) + if getattr(func, '__x_use_name__', False): + new_name = func.__name__ + else: + new_name = '%s%s%d' % (name, _SEPARATOR, idx) + assert new_name not in dct, ( + 'Name of parameterized test case "%s" not unique' % (new_name,)) + dct[new_name] = func + id_suffix[new_name] = getattr(func, '__x_extra_id__', '') + + +class ParameterizedTestCase(basetest.TestCase): + """Base class for test cases using the Parameters decorator.""" + __metaclass__ = TestGeneratorMetaclass + + def _OriginalName(self): + return self._testMethodName.split(_SEPARATOR)[0] + + def __str__(self): + return '%s (%s)' % (self._OriginalName(), _StrClass(self.__class__)) + + def id(self): # pylint: disable=invalid-name + """Returns the descriptive ID of the test. + + This is used internally by the unittesting framework to get a name + for the test to be used in reports. + + Returns: + The test id. + """ + return '%s.%s%s' % (_StrClass(self.__class__), + self._OriginalName(), + self._id_suffix.get(self._testMethodName, '')) + + +def CoopParameterizedTestCase(other_base_class): + """Returns a new base class with a cooperative metaclass base. + + This enables the ParameterizedTestCase to be used in combination + with other base classes that have custom metaclasses, such as + mox.MoxTestBase. + + Only works with metaclasses that do not override type.__new__. + + Example: + + import google3 + import mox + + from google3.testing.pybase import parameterized + + class ExampleTest(parameterized.CoopParameterizedTestCase(mox.MoxTestBase)): + ... + + Args: + other_base_class: (class) A test case base class. + + Returns: + A new class object. + """ + metaclass = type( + 'CoopMetaclass', + (other_base_class.__metaclass__, + TestGeneratorMetaclass), {}) + return metaclass( + 'CoopParameterizedTestCase', + (other_base_class, ParameterizedTestCase), {}) |