Lib/test/test_imp.py

   1 import imp
   2 import unittest
   3 from test import test_support
   4
   5
   6 class LockTests(unittest.TestCase):
   7
   8     """Very basic test of import lock functions."""
   9
  10     def verify_lock_state(self, expected):
  11         self.assertEqual(imp.lock_held(), expected,
  12                              "expected imp.lock_held() to be %r" % expected)
  13     def testLock(self):
  14         LOOPS = 50
  15
  16         # The import lock may already be held, e.g. if the test suite is run
  17         # via "import test.autotest".
  18         lock_held_at_start = imp.lock_held()
  19         self.verify_lock_state(lock_held_at_start)
  20
  21         for i in range(LOOPS):
  22             imp.acquire_lock()
  23             self.verify_lock_state(True)
  24
  25         for i in range(LOOPS):
  26             imp.release_lock()
  27
  28         # The original state should be restored now.
  29         self.verify_lock_state(lock_held_at_start)
  30
  31         if not lock_held_at_start:
  32             try:
  33                 imp.release_lock()
  34             except RuntimeError:
  35                 pass
  36             else:
  37                 self.fail("release_lock() without lock should raise "
  38                             "RuntimeError")
  39
  40 class ReloadTests(unittest.TestCase):
  41
  42     """Very basic tests to make sure that imp.reload() operates just like
  43     reload()."""
  44
  45     def test_source(self):
  46         # XXX (ncoghlan): It would be nice to use test_support.CleanImport
  47         # here, but that breaks because the os module registers some
  48         # handlers in copy_reg on import. Since CleanImport doesn't
  49         # revert that registration, the module is left in a broken
  50         # state after reversion. Reinitialising the module contents
  51         # and just reverting os.environ to its previous state is an OK
  52         # workaround
  53         with test_support.EnvironmentVarGuard():
  54             import os
  55             imp.reload(os)
  56
  57     def test_extension(self):
  58         with test_support.CleanImport('time'):
  59             import time
  60             imp.reload(time)
  61
  62     def test_builtin(self):
  63         with test_support.CleanImport('marshal'):
  64             import marshal
  65             imp.reload(marshal)
  66
  67
  68 def test_main():
  69     tests = [
  70         ReloadTests,
  71     ]
  72     try:
  73         import thread
  74     except ImportError:
  75         pass
  76     else:
  77         tests.append(LockTests)
  78     test_support.run_unittest(*tests)
  79
  80 if __name__ == "__main__":
  81     test_main()