cpython/Lib/test/test_importlib/util.py

226 lines
7.1 KiB
Python

from contextlib import contextmanager
from importlib import util, invalidate_caches
import os.path
from test import support
import unittest
import sys
import types
def import_importlib(module_name):
"""Import a module from importlib both w/ and w/o _frozen_importlib."""
fresh = ('importlib',) if '.' in module_name else ()
frozen = support.import_fresh_module(module_name)
source = support.import_fresh_module(module_name, fresh=fresh,
blocked=('_frozen_importlib',))
return frozen, source
def test_both(test_class, **kwargs):
frozen_tests = types.new_class('Frozen_'+test_class.__name__,
(test_class, unittest.TestCase))
source_tests = types.new_class('Source_'+test_class.__name__,
(test_class, unittest.TestCase))
frozen_tests.__module__ = source_tests.__module__ = test_class.__module__
for attr, (frozen_value, source_value) in kwargs.items():
setattr(frozen_tests, attr, frozen_value)
setattr(source_tests, attr, source_value)
return frozen_tests, source_tests
CASE_INSENSITIVE_FS = True
# Windows is the only OS that is *always* case-insensitive
# (OS X *can* be case-sensitive).
if sys.platform not in ('win32', 'cygwin'):
changed_name = __file__.upper()
if changed_name == __file__:
changed_name = __file__.lower()
if not os.path.exists(changed_name):
CASE_INSENSITIVE_FS = False
def case_insensitive_tests(test):
"""Class decorator that nullifies tests requiring a case-insensitive
file system."""
return unittest.skipIf(not CASE_INSENSITIVE_FS,
"requires a case-insensitive filesystem")(test)
def submodule(parent, name, pkg_dir, content=''):
path = os.path.join(pkg_dir, name + '.py')
with open(path, 'w') as subfile:
subfile.write(content)
return '{}.{}'.format(parent, name), path
@contextmanager
def uncache(*names):
"""Uncache a module from sys.modules.
A basic sanity check is performed to prevent uncaching modules that either
cannot/shouldn't be uncached.
"""
for name in names:
if name in ('sys', 'marshal', 'imp'):
raise ValueError(
"cannot uncache {0}".format(name))
try:
del sys.modules[name]
except KeyError:
pass
try:
yield
finally:
for name in names:
try:
del sys.modules[name]
except KeyError:
pass
@contextmanager
def temp_module(name, content='', *, pkg=False):
conflicts = [n for n in sys.modules if n.partition('.')[0] == name]
with support.temp_cwd(None) as cwd:
with uncache(name, *conflicts):
with support.DirsOnSysPath(cwd):
invalidate_caches()
location = os.path.join(cwd, name)
if pkg:
modpath = os.path.join(location, '__init__.py')
os.mkdir(name)
else:
modpath = location + '.py'
if content is None:
# Make sure the module file gets created.
content = ''
if content is not None:
# not a namespace package
with open(modpath, 'w') as modfile:
modfile.write(content)
yield location
@contextmanager
def import_state(**kwargs):
"""Context manager to manage the various importers and stored state in the
sys module.
The 'modules' attribute is not supported as the interpreter state stores a
pointer to the dict that the interpreter uses internally;
reassigning to sys.modules does not have the desired effect.
"""
originals = {}
try:
for attr, default in (('meta_path', []), ('path', []),
('path_hooks', []),
('path_importer_cache', {})):
originals[attr] = getattr(sys, attr)
if attr in kwargs:
new_value = kwargs[attr]
del kwargs[attr]
else:
new_value = default
setattr(sys, attr, new_value)
if len(kwargs):
raise ValueError(
'unrecognized arguments: {0}'.format(kwargs.keys()))
yield
finally:
for attr, value in originals.items():
setattr(sys, attr, value)
class _ImporterMock:
"""Base class to help with creating importer mocks."""
def __init__(self, *names, module_code={}):
self.modules = {}
self.module_code = {}
for name in names:
if not name.endswith('.__init__'):
import_name = name
else:
import_name = name[:-len('.__init__')]
if '.' not in name:
package = None
elif import_name == name:
package = name.rsplit('.', 1)[0]
else:
package = import_name
module = types.ModuleType(import_name)
module.__loader__ = self
module.__file__ = '<mock __file__>'
module.__package__ = package
module.attr = name
if import_name != name:
module.__path__ = ['<mock __path__>']
self.modules[import_name] = module
if import_name in module_code:
self.module_code[import_name] = module_code[import_name]
def __getitem__(self, name):
return self.modules[name]
def __enter__(self):
self._uncache = uncache(*self.modules.keys())
self._uncache.__enter__()
return self
def __exit__(self, *exc_info):
self._uncache.__exit__(None, None, None)
class mock_modules(_ImporterMock):
"""Importer mock using PEP 302 APIs."""
def find_module(self, fullname, path=None):
if fullname not in self.modules:
return None
else:
return self
def load_module(self, fullname):
if fullname not in self.modules:
raise ImportError
else:
sys.modules[fullname] = self.modules[fullname]
if fullname in self.module_code:
try:
self.module_code[fullname]()
except Exception:
del sys.modules[fullname]
raise
return self.modules[fullname]
class mock_spec(_ImporterMock):
"""Importer mock using PEP 451 APIs."""
def find_spec(self, fullname, path=None, parent=None):
try:
module = self.modules[fullname]
except KeyError:
return None
is_package = hasattr(module, '__path__')
spec = util.spec_from_file_location(
fullname, module.__file__, loader=self,
submodule_search_locations=getattr(module, '__path__', None))
return spec
def create_module(self, spec):
if spec.name not in self.modules:
raise ImportError
return self.modules[spec.name]
def exec_module(self, module):
try:
self.module_code[module.__spec__.name]()
except KeyError:
pass