mirror of
https://github.com/python/cpython.git
synced 2025-11-04 03:44:55 +00:00
132 lines
4.2 KiB
Python
132 lines
4.2 KiB
Python
import importlib
|
|
from importlib import abc
|
|
from importlib import util
|
|
import unittest
|
|
|
|
from . import util as test_util
|
|
|
|
|
|
class CollectInit:
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
self.args = args
|
|
self.kwargs = kwargs
|
|
|
|
def exec_module(self, module):
|
|
return self
|
|
|
|
|
|
class LazyLoaderFactoryTests(unittest.TestCase):
|
|
|
|
def test_init(self):
|
|
factory = util.LazyLoader.factory(CollectInit)
|
|
# E.g. what importlib.machinery.FileFinder instantiates loaders with
|
|
# plus keyword arguments.
|
|
lazy_loader = factory('module name', 'module path', kw='kw')
|
|
loader = lazy_loader.loader
|
|
self.assertEqual(('module name', 'module path'), loader.args)
|
|
self.assertEqual({'kw': 'kw'}, loader.kwargs)
|
|
|
|
def test_validation(self):
|
|
# No exec_module(), no lazy loading.
|
|
with self.assertRaises(TypeError):
|
|
util.LazyLoader.factory(object)
|
|
|
|
|
|
class TestingImporter(abc.MetaPathFinder, abc.Loader):
|
|
|
|
module_name = 'lazy_loader_test'
|
|
mutated_name = 'changed'
|
|
loaded = None
|
|
source_code = 'attr = 42; __name__ = {!r}'.format(mutated_name)
|
|
|
|
def find_spec(self, name, path, target=None):
|
|
if name != self.module_name:
|
|
return None
|
|
return util.spec_from_loader(name, util.LazyLoader(self))
|
|
|
|
def exec_module(self, module):
|
|
exec(self.source_code, module.__dict__)
|
|
self.loaded = module
|
|
|
|
|
|
class LazyLoaderTests(unittest.TestCase):
|
|
|
|
def test_init(self):
|
|
with self.assertRaises(TypeError):
|
|
util.LazyLoader(object)
|
|
|
|
def new_module(self, source_code=None):
|
|
loader = TestingImporter()
|
|
if source_code is not None:
|
|
loader.source_code = source_code
|
|
spec = util.spec_from_loader(TestingImporter.module_name,
|
|
util.LazyLoader(loader))
|
|
module = spec.loader.create_module(spec)
|
|
module.__spec__ = spec
|
|
module.__loader__ = spec.loader
|
|
spec.loader.exec_module(module)
|
|
# Module is now lazy.
|
|
self.assertIsNone(loader.loaded)
|
|
return module
|
|
|
|
def test_e2e(self):
|
|
# End-to-end test to verify the load is in fact lazy.
|
|
importer = TestingImporter()
|
|
assert importer.loaded is None
|
|
with test_util.uncache(importer.module_name):
|
|
with test_util.import_state(meta_path=[importer]):
|
|
module = importlib.import_module(importer.module_name)
|
|
self.assertIsNone(importer.loaded)
|
|
# Trigger load.
|
|
self.assertEqual(module.__loader__, importer)
|
|
self.assertIsNotNone(importer.loaded)
|
|
self.assertEqual(module, importer.loaded)
|
|
|
|
def test_attr_unchanged(self):
|
|
# An attribute only mutated as a side-effect of import should not be
|
|
# changed needlessly.
|
|
module = self.new_module()
|
|
self.assertEqual(TestingImporter.mutated_name, module.__name__)
|
|
|
|
def test_new_attr(self):
|
|
# A new attribute should persist.
|
|
module = self.new_module()
|
|
module.new_attr = 42
|
|
self.assertEqual(42, module.new_attr)
|
|
|
|
def test_mutated_preexisting_attr(self):
|
|
# Changing an attribute that already existed on the module --
|
|
# e.g. __name__ -- should persist.
|
|
module = self.new_module()
|
|
module.__name__ = 'bogus'
|
|
self.assertEqual('bogus', module.__name__)
|
|
|
|
def test_mutated_attr(self):
|
|
# Changing an attribute that comes into existence after an import
|
|
# should persist.
|
|
module = self.new_module()
|
|
module.attr = 6
|
|
self.assertEqual(6, module.attr)
|
|
|
|
def test_delete_eventual_attr(self):
|
|
# Deleting an attribute should stay deleted.
|
|
module = self.new_module()
|
|
del module.attr
|
|
self.assertFalse(hasattr(module, 'attr'))
|
|
|
|
def test_delete_preexisting_attr(self):
|
|
module = self.new_module()
|
|
del module.__name__
|
|
self.assertFalse(hasattr(module, '__name__'))
|
|
|
|
def test_module_substitution_error(self):
|
|
source_code = 'import sys; sys.modules[__name__] = 42'
|
|
module = self.new_module(source_code)
|
|
with test_util.uncache(TestingImporter.module_name):
|
|
with self.assertRaises(ValueError):
|
|
module.__name__
|
|
|
|
|
|
if __name__ == '__main__':
|
|
unittest.main()
|