import os import sys import shutil import string import random import tempfile import unittest from importlib.util import cache_from_source from test.support import run_unittest, create_empty_file class TestImport(unittest.TestCase): def __init__(self, *args, **kw): self.package_name = 'PACKAGE_' while self.package_name in sys.modules: self.package_name += random.choose(string.ascii_letters) self.module_name = self.package_name + '.foo' unittest.TestCase.__init__(self, *args, **kw) def remove_modules(self): for module_name in (self.package_name, self.module_name): if module_name in sys.modules: del sys.modules[module_name] def setUp(self): self.test_dir = tempfile.mkdtemp() sys.path.append(self.test_dir) self.package_dir = os.path.join(self.test_dir, self.package_name) os.mkdir(self.package_dir) create_empty_file(os.path.join(self.package_dir, '__init__.py')) self.module_path = os.path.join(self.package_dir, 'foo.py') def tearDown(self): shutil.rmtree(self.test_dir) self.assertNotEqual(sys.path.count(self.test_dir), 0) sys.path.remove(self.test_dir) self.remove_modules() def rewrite_file(self, contents): compiled_path = cache_from_source(self.module_path) if os.path.exists(compiled_path): os.remove(compiled_path) with open(self.module_path, 'w') as f: f.write(contents) def test_package_import__semantics(self): # Generate a couple of broken modules to try importing. # ...try loading the module when there's a SyntaxError self.rewrite_file('for') try: __import__(self.module_name) except SyntaxError: pass else: raise RuntimeError('Failed to induce SyntaxError') # self.fail()? self.assertNotIn(self.module_name, sys.modules) self.assertFalse(hasattr(sys.modules[self.package_name], 'foo')) # ...make up a variable name that isn't bound in __builtins__ var = 'a' while var in dir(__builtins__): var += random.choose(string.ascii_letters) # ...make a module that just contains that self.rewrite_file(var) try: __import__(self.module_name) except NameError: pass else: raise RuntimeError('Failed to induce NameError.') # ...now change the module so that the NameError doesn't # happen self.rewrite_file('%s = 1' % var) module = __import__(self.module_name).foo self.assertEqual(getattr(module, var), 1) def test_main(): run_unittest(TestImport) if __name__ == "__main__": test_main()