CasperSecurity
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Tests for miscellaneous behaviors of the top-level L{twisted} package (ie, for
the code in C{twisted/__init__.py}.
"""
import sys
from types import ModuleType
from twisted.trial.unittest import TestCase
# This is somewhat generally useful and should probably be part of a public API
# somewhere. See #5977.
class SetAsideModule:
"""
L{SetAsideModule} is a context manager for temporarily removing a module
from C{sys.modules}.
@ivar name: The name of the module to remove.
"""
def __init__(self, name):
self.name = name
def _unimport(self, name):
"""
Find the given module and all of its hierarchically inferior modules in
C{sys.modules}, remove them from it, and return whatever was found.
"""
modules = {
moduleName: module
for (moduleName, module) in list(sys.modules.items())
if (moduleName == self.name or moduleName.startswith(self.name + "."))
}
for name in modules:
del sys.modules[name]
return modules
def __enter__(self):
self.modules = self._unimport(self.name)
def __exit__(self, excType, excValue, traceback):
self._unimport(self.name)
sys.modules.update(self.modules)
def _install(modules):
"""
Take a mapping defining a package and turn it into real C{ModuleType}
instances in C{sys.modules}.
Consider these example::
a = {"foo": "bar"}
b = {"twisted": {"__version__": "42.6"}}
c = {"twisted": {"plugin": {"getPlugins": stub}}}
C{_install(a)} will place an item into C{sys.modules} with C{"foo"} as the
key and C{"bar" as the value.
C{_install(b)} will place an item into C{sys.modules} with C{"twisted"} as
the key. The value will be a new module object. The module will have a
C{"__version__"} attribute with C{"42.6"} as the value.
C{_install(c)} will place an item into C{sys.modules} with C{"twisted"} as
the key. The value will be a new module object with a C{"plugin"}
attribute. An item will also be placed into C{sys.modules} with the key
C{"twisted.plugin"} which refers to that module object. That module will
have an attribute C{"getPlugins"} with a value of C{stub}.
@param modules: A mapping from names to definitions of modules. The names
are native strings like C{"twisted"} or C{"unittest"}. Values may be
arbitrary objects. Any value which is not a dictionary will be added to
C{sys.modules} unmodified. Any dictionary value indicates the value is
a new module and its items define the attributes of that module. The
definition of this structure is recursive, so a value in the dictionary
may be a dictionary to trigger another level of processing.
@return: L{None}
"""
result = {}
_makePackages(None, modules, result)
sys.modules.update(result)
def _makePackages(parent, attributes, result):
"""
Construct module objects (for either modules or packages).
@param parent: L{None} or a module object which is the Python package
containing all of the modules being created by this function call. Its
name will be prepended to the name of all created modules.
@param attributes: A mapping giving the attributes of the particular module
object this call is creating.
@param result: A mapping which is populated with all created module names.
This is suitable for use in updating C{sys.modules}.
@return: A mapping of all of the attributes created by this call. This is
suitable for populating the dictionary of C{parent}.
@see: L{_install}.
"""
attrs = {}
for (name, value) in list(attributes.items()):
if parent is None:
if isinstance(value, dict):
module = ModuleType(name)
module.__dict__.update(_makePackages(module, value, result))
result[name] = module
else:
result[name] = value
else:
if isinstance(value, dict):
module = ModuleType(parent.__name__ + "." + name)
module.__dict__.update(_makePackages(module, value, result))
result[parent.__name__ + "." + name] = module
attrs[name] = module
else:
attrs[name] = value
return attrs
class MakePackagesTests(TestCase):
"""
Tests for L{_makePackages}, a helper for populating C{sys.modules} with
fictional modules.
"""
def test_nonModule(self):
"""
A non-C{dict} value in the attributes dictionary passed to L{_makePackages}
is preserved unchanged in the return value.
"""
modules = {}
_makePackages(None, dict(reactor="reactor"), modules)
self.assertEqual(modules, dict(reactor="reactor"))
def test_moduleWithAttribute(self):
"""
A C{dict} value in the attributes dictionary passed to L{_makePackages}
is turned into a L{ModuleType} instance with attributes populated from
the items of that C{dict} value.
"""
modules = {}
_makePackages(None, dict(twisted=dict(version="123")), modules)
self.assertIsInstance(modules, dict)
self.assertIsInstance(modules["twisted"], ModuleType)
self.assertEqual("twisted", modules["twisted"].__name__)
self.assertEqual("123", modules["twisted"].version)
def test_packageWithModule(self):
"""
Processing of the attributes dictionary is recursive, so a C{dict} value
it contains may itself contain a C{dict} value to the same effect.
"""
modules = {}
_makePackages(None, dict(twisted=dict(web=dict(version="321"))), modules)
self.assertIsInstance(modules, dict)
self.assertIsInstance(modules["twisted"], ModuleType)
self.assertEqual("twisted", modules["twisted"].__name__)
self.assertIsInstance(modules["twisted"].web, ModuleType)
self.assertEqual("twisted.web", modules["twisted"].web.__name__)
self.assertEqual("321", modules["twisted"].web.version)