text: from importlib import _bootstrap
  import sys
  from test import support
  import unittest
  
  from .. import util
  
  frozen_machinery, source_machinery = util.import_importlib('importlib.machinery')
  
  
  # XXX find_spec tests
  
  @unittest.skipIf(util.EXTENSIONS.filename is None, '_testcapi not available')
  @util.case_insensitive_tests
  class ExtensionModuleCaseSensitivityTest(object):
  
      def find_module(self):
          good_name = util.EXTENSIONS.name
          bad_name = good_name.upper()
          assert good_name != bad_name
          finder = self.machinery.FileFinder(util.EXTENSIONS.path,
                                            (self.machinery.ExtensionFileLoader,
                                             self.machinery.EXTENSION_SUFFIXES))
          return finder.find_module(bad_name)
  
      def test_case_sensitive(self):
          with support.EnvironmentVarGuard() as env:
              env.unset('PYTHONCASEOK')
              if b'PYTHONCASEOK' in _bootstrap._os.environ:
                  self.skipTest('os.environ changes not reflected in '
                                '_os.environ')
              loader = self.find_module()
              self.assertIsNone(loader)
  
      def test_case_insensitivity(self):
          with support.EnvironmentVarGuard() as env:
              env.set('PYTHONCASEOK', '1')
              if b'PYTHONCASEOK' not in _bootstrap._os.environ:
                  self.skipTest('os.environ changes not reflected in '
                                '_os.environ')
              loader = self.find_module()
              self.assertTrue(hasattr(loader, 'load_module'))
  
  Frozen_ExtensionCaseSensitivity, Source_ExtensionCaseSensitivity = util.test_both(
          ExtensionModuleCaseSensitivityTest,
          machinery=[frozen_machinery, source_machinery])
  
  
  if __name__ == '__main__':
      unittest.main()
  