text: #!/usr/bin/env python
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  """Tests the --help flag of Google C++ Testing Framework.
  
  SYNOPSIS
         gtest_help_test.py --build_dir=BUILD/DIR
           # where BUILD/DIR contains the built gtest_help_test_ file.
         gtest_help_test.py
  """
  
  __author__ = 'wan@google.com (Zhanyong Wan)'
  
  import os
  import re
  import gtest_test_utils
  
  IS_LINUX = os.name == 'posix' and os.uname()[0] == 'Linux'
  IS_WINDOWS = os.name == 'nt'
  
  PROGRAM_PATH = gtest_test_utils.GetTestExecutablePath('gtest_help_test_')
  FLAG_PREFIX = '--gtest_'
  DEATH_TEST_STYLE_FLAG = FLAG_PREFIX + 'death_test_style'
  STREAM_RESULT_TO_FLAG = FLAG_PREFIX + 'stream_result_to'
  UNKNOWN_FLAG = FLAG_PREFIX + 'unknown_flag_for_testing'
  LIST_TESTS_FLAG = FLAG_PREFIX + 'list_tests'
  INCORRECT_FLAG_VARIANTS = [re.sub('^--', '-', LIST_TESTS_FLAG),
                             re.sub('^--', '/', LIST_TESTS_FLAG),
                             re.sub('_', '-', LIST_TESTS_FLAG)]
  INTERNAL_FLAG_FOR_TESTING = FLAG_PREFIX + 'internal_flag_for_testing'
  
  SUPPORTS_DEATH_TESTS = "DeathTest" in gtest_test_utils.Subprocess(
      [PROGRAM_PATH, LIST_TESTS_FLAG]).output
  
  # The help message must match this regex.
  HELP_REGEX = re.compile(
      FLAG_PREFIX + r'list_tests.*' +
      FLAG_PREFIX + r'filter=.*' +
      FLAG_PREFIX + r'also_run_disabled_tests.*' +
      FLAG_PREFIX + r'repeat=.*' +
      FLAG_PREFIX + r'shuffle.*' +
      FLAG_PREFIX + r'random_seed=.*' +
      FLAG_PREFIX + r'color=.*' +
      FLAG_PREFIX + r'print_time.*' +
      FLAG_PREFIX + r'output=.*' +
      FLAG_PREFIX + r'break_on_failure.*' +
      FLAG_PREFIX + r'throw_on_failure.*' +
      FLAG_PREFIX + r'catch_exceptions=0.*',
      re.DOTALL)
  
  
  def RunWithFlag(flag):
      """Runs gtest_help_test_ with the given flag.
  
      Returns:
        the exit code and the text output as a tuple.
      Args:
        flag: the command-line flag to pass to gtest_help_test_, or None.
      """
  
      if flag is None:
          command = [PROGRAM_PATH]
      else:
          command = [PROGRAM_PATH, flag]
      child = gtest_test_utils.Subprocess(command)
      return child.exit_code, child.output
  
  
  class GTestHelpTest(gtest_test_utils.TestCase):
      """Tests the --help flag and its equivalent forms."""
  
      def TestHelpFlag(self, flag):
          """Verifies correct behavior when help flag is specified.
  
          The right message must be printed and the tests must
          skipped when the given flag is specified.
  
          Args:
            flag:  A flag to pass to the binary or None.
          """
  
          exit_code, output = RunWithFlag(flag)
          self.assertEquals(0, exit_code)
          self.assert_(HELP_REGEX.search(output), output)
  
          if IS_LINUX:
              self.assert_(STREAM_RESULT_TO_FLAG in output, output)
          else:
              self.assert_(STREAM_RESULT_TO_FLAG not in output, output)
  
          if SUPPORTS_DEATH_TESTS and not IS_WINDOWS:
              self.assert_(DEATH_TEST_STYLE_FLAG in output, output)
          else:
              self.assert_(DEATH_TEST_STYLE_FLAG not in output, output)
  
      def TestNonHelpFlag(self, flag):
          """Verifies correct behavior when no help flag is specified.
  
          Verifies that when no help flag is specified, the tests are run
          and the help message is not printed.
  
          Args:
            flag:  A flag to pass to the binary or None.
          """
  
          exit_code, output = RunWithFlag(flag)
          self.assert_(exit_code != 0)
          self.assert_(not HELP_REGEX.search(output), output)
  
      def testPrintsHelpWithFullFlag(self):
          self.TestHelpFlag('--help')
  
      def testPrintsHelpWithShortFlag(self):
          self.TestHelpFlag('-h')
  
      def testPrintsHelpWithQuestionFlag(self):
          self.TestHelpFlag('-?')
  
      def testPrintsHelpWithWindowsStyleQuestionFlag(self):
          self.TestHelpFlag('/?')
  
      def testPrintsHelpWithUnrecognizedGoogleTestFlag(self):
          self.TestHelpFlag(UNKNOWN_FLAG)
  
      def testPrintsHelpWithIncorrectFlagStyle(self):
          for incorrect_flag in INCORRECT_FLAG_VARIANTS:
              self.TestHelpFlag(incorrect_flag)
  
      def testRunsTestsWithoutHelpFlag(self):
          """Verifies that when no help flag is specified, the tests are run
          and the help message is not printed."""
  
          self.TestNonHelpFlag(None)
  
      def testRunsTestsWithGtestInternalFlag(self):
          """Verifies that the tests are run and no help message is printed when
          a flag starting with Google Test prefix and 'internal_' is supplied."""
  
          self.TestNonHelpFlag(INTERNAL_FLAG_FOR_TESTING)
  
  
  if __name__ == '__main__':
      gtest_test_utils.Main()
  