cpython/Lib/test/test_importlib/test_api.py
Brett Cannon 3fe35e6503 Issue #18193: Add importlib.reload(), documenting (but not
implementing in code) the deprecation of imp.reload().

Thanks to Berker Peksag for the patch.
2013-06-14 15:04:26 -04:00

222 lines
8.3 KiB
Python

from . import util
import imp
import importlib
from importlib import _bootstrap
from importlib import machinery
import sys
from test import support
import types
import unittest
class ImportModuleTests(unittest.TestCase):
"""Test importlib.import_module."""
def test_module_import(self):
# Test importing a top-level module.
with util.mock_modules('top_level') as mock:
with util.import_state(meta_path=[mock]):
module = importlib.import_module('top_level')
self.assertEqual(module.__name__, 'top_level')
def test_absolute_package_import(self):
# Test importing a module from a package with an absolute name.
pkg_name = 'pkg'
pkg_long_name = '{0}.__init__'.format(pkg_name)
name = '{0}.mod'.format(pkg_name)
with util.mock_modules(pkg_long_name, name) as mock:
with util.import_state(meta_path=[mock]):
module = importlib.import_module(name)
self.assertEqual(module.__name__, name)
def test_shallow_relative_package_import(self):
# Test importing a module from a package through a relative import.
pkg_name = 'pkg'
pkg_long_name = '{0}.__init__'.format(pkg_name)
module_name = 'mod'
absolute_name = '{0}.{1}'.format(pkg_name, module_name)
relative_name = '.{0}'.format(module_name)
with util.mock_modules(pkg_long_name, absolute_name) as mock:
with util.import_state(meta_path=[mock]):
importlib.import_module(pkg_name)
module = importlib.import_module(relative_name, pkg_name)
self.assertEqual(module.__name__, absolute_name)
def test_deep_relative_package_import(self):
modules = ['a.__init__', 'a.b.__init__', 'a.c']
with util.mock_modules(*modules) as mock:
with util.import_state(meta_path=[mock]):
importlib.import_module('a')
importlib.import_module('a.b')
module = importlib.import_module('..c', 'a.b')
self.assertEqual(module.__name__, 'a.c')
def test_absolute_import_with_package(self):
# Test importing a module from a package with an absolute name with
# the 'package' argument given.
pkg_name = 'pkg'
pkg_long_name = '{0}.__init__'.format(pkg_name)
name = '{0}.mod'.format(pkg_name)
with util.mock_modules(pkg_long_name, name) as mock:
with util.import_state(meta_path=[mock]):
importlib.import_module(pkg_name)
module = importlib.import_module(name, pkg_name)
self.assertEqual(module.__name__, name)
def test_relative_import_wo_package(self):
# Relative imports cannot happen without the 'package' argument being
# set.
with self.assertRaises(TypeError):
importlib.import_module('.support')
def test_loaded_once(self):
# Issue #13591: Modules should only be loaded once when
# initializing the parent package attempts to import the
# module currently being imported.
b_load_count = 0
def load_a():
importlib.import_module('a.b')
def load_b():
nonlocal b_load_count
b_load_count += 1
code = {'a': load_a, 'a.b': load_b}
modules = ['a.__init__', 'a.b']
with util.mock_modules(*modules, module_code=code) as mock:
with util.import_state(meta_path=[mock]):
importlib.import_module('a.b')
self.assertEqual(b_load_count, 1)
class FindLoaderTests(unittest.TestCase):
class FakeMetaFinder:
@staticmethod
def find_module(name, path=None): return name, path
def test_sys_modules(self):
# If a module with __loader__ is in sys.modules, then return it.
name = 'some_mod'
with util.uncache(name):
module = imp.new_module(name)
loader = 'a loader!'
module.__loader__ = loader
sys.modules[name] = module
found = importlib.find_loader(name)
self.assertEqual(loader, found)
def test_sys_modules_loader_is_None(self):
# If sys.modules[name].__loader__ is None, raise ValueError.
name = 'some_mod'
with util.uncache(name):
module = imp.new_module(name)
module.__loader__ = None
sys.modules[name] = module
with self.assertRaises(ValueError):
importlib.find_loader(name)
def test_sys_modules_loader_is_not_set(self):
# Should raise ValueError
# Issue #17099
name = 'some_mod'
with util.uncache(name):
module = imp.new_module(name)
try:
del module.__loader__
except AttributeError:
pass
sys.modules[name] = module
with self.assertRaises(ValueError):
importlib.find_loader(name)
def test_success(self):
# Return the loader found on sys.meta_path.
name = 'some_mod'
with util.uncache(name):
with util.import_state(meta_path=[self.FakeMetaFinder]):
self.assertEqual((name, None), importlib.find_loader(name))
def test_success_path(self):
# Searching on a path should work.
name = 'some_mod'
path = 'path to some place'
with util.uncache(name):
with util.import_state(meta_path=[self.FakeMetaFinder]):
self.assertEqual((name, path),
importlib.find_loader(name, path))
def test_nothing(self):
# None is returned upon failure to find a loader.
self.assertIsNone(importlib.find_loader('nevergoingtofindthismodule'))
class ReloadTests(unittest.TestCase):
"""Test module reloading for builtin and extension modules."""
def test_reload_modules(self):
for mod in ('tokenize', 'time', 'marshal'):
with self.subTest(module=mod):
with support.CleanImport(mod):
module = importlib.import_module(mod)
importlib.reload(module)
class InvalidateCacheTests(unittest.TestCase):
def test_method_called(self):
# If defined the method should be called.
class InvalidatingNullFinder:
def __init__(self, *ignored):
self.called = False
def find_module(self, *args):
return None
def invalidate_caches(self):
self.called = True
key = 'gobledeegook'
meta_ins = InvalidatingNullFinder()
path_ins = InvalidatingNullFinder()
sys.meta_path.insert(0, meta_ins)
self.addCleanup(lambda: sys.path_importer_cache.__delitem__(key))
sys.path_importer_cache[key] = path_ins
self.addCleanup(lambda: sys.meta_path.remove(meta_ins))
importlib.invalidate_caches()
self.assertTrue(meta_ins.called)
self.assertTrue(path_ins.called)
def test_method_lacking(self):
# There should be no issues if the method is not defined.
key = 'gobbledeegook'
sys.path_importer_cache[key] = imp.NullImporter('abc')
self.addCleanup(lambda: sys.path_importer_cache.__delitem__(key))
importlib.invalidate_caches() # Shouldn't trigger an exception.
class FrozenImportlibTests(unittest.TestCase):
def test_no_frozen_importlib(self):
# Should be able to import w/o _frozen_importlib being defined.
module = support.import_fresh_module('importlib', blocked=['_frozen_importlib'])
self.assertFalse(isinstance(module.__loader__,
machinery.FrozenImporter))
class StartupTests(unittest.TestCase):
def test_everyone_has___loader__(self):
# Issue #17098: all modules should have __loader__ defined.
for name, module in sys.modules.items():
if isinstance(module, types.ModuleType):
self.assertTrue(hasattr(module, '__loader__'),
'{!r} lacks a __loader__ attribute'.format(name))
if importlib.machinery.BuiltinImporter.find_module(name):
self.assertIsNot(module.__loader__, None)
elif importlib.machinery.FrozenImporter.find_module(name):
self.assertIsNot(module.__loader__, None)
if __name__ == '__main__':
unittest.main()