Lib/test/test_pkgimport.py

   1 import os, sys, string, random, tempfile, unittest
   2
   3 from test.test_support import run_unittest
   4
   5 class TestImport(unittest.TestCase):
   6
   7     def __init__(self, *args, **kw):
   8         self.package_name = 'PACKAGE_'
   9         while self.package_name in sys.modules:
  10             self.package_name += random.choose(string.letters)
  11         self.module_name = self.package_name + '.foo'
  12         unittest.TestCase.__init__(self, *args, **kw)
  13
  14     def remove_modules(self):
  15         for module_name in (self.package_name, self.module_name):
  16             if module_name in sys.modules:
  17                 del sys.modules[module_name]
  18
  19     def setUp(self):
  20         self.test_dir = tempfile.mkdtemp()
  21         sys.path.append(self.test_dir)
  22         self.package_dir = os.path.join(self.test_dir,
  23                                         self.package_name)
  24         os.mkdir(self.package_dir)
  25         open(os.path.join(self.package_dir, '__init__'+os.extsep+'py'), 'w')
  26         self.module_path = os.path.join(self.package_dir, 'foo'+os.extsep+'py')
  27
  28     def tearDown(self):
  29         for file in os.listdir(self.package_dir):
  30             os.remove(os.path.join(self.package_dir, file))
  31         os.rmdir(self.package_dir)
  32         os.rmdir(self.test_dir)
  33         self.assertNotEqual(sys.path.count(self.test_dir), 0)
  34         sys.path.remove(self.test_dir)
  35         self.remove_modules()
  36
  37     def rewrite_file(self, contents):
  38         for extension in "co":
  39             compiled_path = self.module_path + extension
  40             if os.path.exists(compiled_path):
  41                 os.remove(compiled_path)
  42         f = open(self.module_path, 'w')
  43         f.write(contents)
  44         f.close()
  45
  46     def test_package_import__semantics(self):
  47
  48         # Generate a couple of broken modules to try importing.
  49
  50         # ...try loading the module when there's a SyntaxError
  51         self.rewrite_file('for')
  52         try: __import__(self.module_name)
  53         except SyntaxError: pass
  54         else: raise RuntimeError, 'Failed to induce SyntaxError'
  55         self.assertNotIn(self.module_name, sys.modules)
  56         self.assertFalse(hasattr(sys.modules[self.package_name], 'foo'))
  57
  58         # ...make up a variable name that isn't bound in __builtins__
  59         var = 'a'
  60         while var in dir(__builtins__):
  61             var += random.choose(string.letters)
  62
  63         # ...make a module that just contains that
  64         self.rewrite_file(var)
  65
  66         try: __import__(self.module_name)
  67         except NameError: pass
  68         else: raise RuntimeError, 'Failed to induce NameError.'
  69
  70         # ...now  change  the module  so  that  the NameError  doesn't
  71         # happen
  72         self.rewrite_file('%s = 1' % var)
  73         module = __import__(self.module_name).foo
  74         self.assertEqual(getattr(module, var), 1)
  75
  76
  77 def test_main():
  78     run_unittest(TestImport)
  79
  80
  81 if __name__ == "__main__":
  82     test_main()