Viewing file:  test_importhooks.py (6.71 KB) -rw-r--r--
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import sys
import imp
import os
import unittest
from test import test_support
test_src = """\
def get_name():
return __name__
def get_file():
return __file__
"""
reload_src = test_src+"""\
reloaded = True
"""
test_co = compile(test_src, "<???>", "exec")
reload_co = compile(reload_src, "<???>", "exec")
test_path = "!!!_test_!!!"
class ImportTracker:
"""Importer that only tracks attempted imports."""
def __init__(self):
self.imports = []
def find_module(self, fullname, path=None):
self.imports.append(fullname)
return None
class TestImporter:
modules = {
"hooktestmodule": (False, test_co),
"hooktestpackage": (True, test_co),
"hooktestpackage.sub": (True, test_co),
"hooktestpackage.sub.subber": (False, test_co),
"reloadmodule": (False, test_co),
}
def __init__(self, path=test_path):
if path != test_path:
# if out class is on sys.path_hooks, we must raise
# ImportError for any path item that we can't handle.
raise ImportError
self.path = path
def _get__path__(self):
raise NotImplementedError
def find_module(self, fullname, path=None):
if fullname in self.modules:
return self
else:
return None
def load_module(self, fullname):
ispkg, code = self.modules[fullname]
mod = sys.modules.setdefault(fullname,imp.new_module(fullname))
mod.__file__ = "<%s>" % self.__class__.__name__
mod.__loader__ = self
if ispkg:
mod.__path__ = self._get__path__()
exec code in mod.__dict__
return mod
class MetaImporter(TestImporter):
def _get__path__(self):
return []
class PathImporter(TestImporter):
def _get__path__(self):
return [self.path]
class ImportBlocker:
"""Place an ImportBlocker instance on sys.meta_path and you
can be sure the modules you specified can't be imported, even
if it's a builtin."""
def __init__(self, *namestoblock):
self.namestoblock = dict.fromkeys(namestoblock)
def find_module(self, fullname, path=None):
if fullname in self.namestoblock:
return self
return None
def load_module(self, fullname):
raise ImportError, "I dare you"
class ImpWrapper:
def __init__(self, path=None):
if path is not None and not os.path.isdir(path):
raise ImportError
self.path = path
def find_module(self, fullname, path=None):
subname = fullname.split(".")[-1]
if subname != fullname and self.path is None:
return None
if self.path is None:
path = None
else:
path = [self.path]
try:
file, filename, stuff = imp.find_module(subname, path)
except ImportError:
return None
return ImpLoader(file, filename, stuff)
class ImpLoader:
def __init__(self, file, filename, stuff):
self.file = file
self.filename = filename
self.stuff = stuff
def load_module(self, fullname):
mod = imp.load_module(fullname, self.file, self.filename, self.stuff)
if self.file:
self.file.close()
mod.__loader__ = self # for introspection
return mod
class ImportHooksBaseTestCase(unittest.TestCase):
def setUp(self):
self.path = sys.path[:]
self.meta_path = sys.meta_path[:]
self.path_hooks = sys.path_hooks[:]
sys.path_importer_cache.clear()
self.tracker = ImportTracker()
sys.meta_path.insert(0, self.tracker)
def tearDown(self):
sys.path[:] = self.path
sys.meta_path[:] = self.meta_path
sys.path_hooks[:] = self.path_hooks
sys.path_importer_cache.clear()
for fullname in self.tracker.imports:
if fullname in sys.modules:
del sys.modules[fullname]
class ImportHooksTestCase(ImportHooksBaseTestCase):
def doTestImports(self, importer=None):
import hooktestmodule
import hooktestpackage
import hooktestpackage.sub
import hooktestpackage.sub.subber
self.assertEqual(hooktestmodule.get_name(),
"hooktestmodule")
self.assertEqual(hooktestpackage.get_name(),
"hooktestpackage")
self.assertEqual(hooktestpackage.sub.get_name(),
"hooktestpackage.sub")
self.assertEqual(hooktestpackage.sub.subber.get_name(),
"hooktestpackage.sub.subber")
if importer:
self.assertEqual(hooktestmodule.__loader__, importer)
self.assertEqual(hooktestpackage.__loader__, importer)
self.assertEqual(hooktestpackage.sub.__loader__, importer)
self.assertEqual(hooktestpackage.sub.subber.__loader__, importer)
TestImporter.modules['reloadmodule'] = (False, test_co)
import reloadmodule
self.failIf(hasattr(reloadmodule,'reloaded'))
TestImporter.modules['reloadmodule'] = (False, reload_co)
reload(reloadmodule)
self.failUnless(hasattr(reloadmodule,'reloaded'))
def testMetaPath(self):
i = MetaImporter()
sys.meta_path.append(i)
self.doTestImports(i)
def testPathHook(self):
sys.path_hooks.append(PathImporter)
sys.path.append(test_path)
self.doTestImports()
def testBlocker(self):
mname = "exceptions" # an arbitrary harmless builtin module
if mname in sys.modules:
del sys.modules[mname]
sys.meta_path.append(ImportBlocker(mname))
try:
__import__(mname)
except ImportError:
pass
else:
self.fail("'%s' was not supposed to be importable" % mname)
def testImpWrapper(self):
i = ImpWrapper()
sys.meta_path.append(i)
sys.path_hooks.append(ImpWrapper)
mnames = ("colorsys", "urlparse", "distutils.core", "compiler.misc")
for mname in mnames:
parent = mname.split(".")[0]
for n in sys.modules.keys():
if n.startswith(parent):
del sys.modules[n]
for mname in mnames:
m = __import__(mname, globals(), locals(), ["__dummy__"])
m.__loader__ # to make sure we actually handled the import
# Delete urllib from modules because urlparse was imported above.
# Without this hack, test_socket_ssl fails if run in this order:
# regrtest.py test_codecmaps_tw test_importhooks test_socket_ssl
try:
del sys.modules['urllib']
except KeyError:
pass
def test_main():
test_support.run_unittest(ImportHooksTestCase)
if __name__ == "__main__":
test_main()
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