#!/usr/bin/env python
#
# Copyright 2009, Google Inc.
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"""Tests the --help flag of Google C++ Testing and Mocking Framework.

SYNOPSIS
       gtest_help_test.py --build_dir=BUILD/DIR
         # where BUILD/DIR contains the built gtest_help_test_ file.
       gtest_help_test.py
"""

import os
import re
import sys
from googletest.test import gtest_test_utils


IS_LINUX = os.name == 'posix' and os.uname()[0] == 'Linux'
IS_GNUHURD = os.name == 'posix' and os.uname()[0] == 'GNU'
IS_GNUKFREEBSD = os.name == 'posix' and os.uname()[0] == 'GNU/kFreeBSD'
IS_OPENBSD = os.name == 'posix' and os.uname()[0] == 'OpenBSD'
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_GTEST_PREFIXED_FLAG = FLAG_PREFIX + 'unknown_flag_for_testing'
LIST_TESTS_FLAG = FLAG_PREFIX + 'list_tests'
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
)

HAS_ABSL_FLAGS = '--has_absl_flags' in sys.argv

# 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'brief.*'
    + 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)
    if HAS_ABSL_FLAGS:
      # The Abseil flags library prints the ProgramUsageMessage() with
      # --help and returns 1.
      self.assertEqual(1, exit_code)
    else:
      self.assertEqual(0, exit_code)

    self.assertTrue(HELP_REGEX.search(output), output)

    if IS_LINUX or IS_GNUHURD or IS_GNUKFREEBSD or IS_OPENBSD:
      self.assertIn(STREAM_RESULT_TO_FLAG, output)
    else:
      self.assertNotIn(STREAM_RESULT_TO_FLAG, output)

    if SUPPORTS_DEATH_TESTS and not IS_WINDOWS:
      self.assertIn(DEATH_TEST_STYLE_FLAG, output)
    else:
      self.assertNotIn(DEATH_TEST_STYLE_FLAG, output)

  def TestUnknownFlagWithAbseil(self, flag):
    """Verifies correct behavior when an unknown 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.assertEqual(1, exit_code)
    self.assertIn('ERROR: Unknown command line flag', 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.assertNotEqual(exit_code, 0)
    self.assertFalse(HELP_REGEX.search(output), output)

  def testPrintsHelpWithFullFlag(self):
    self.TestHelpFlag('--help')

  def testPrintsHelpWithUnrecognizedGoogleTestFlag(self):
    # The behavior is slightly different when Abseil flags is
    # used. Abseil flags rejects all unknown flags, while the builtin
    # GTest flags implementation interprets an unknown flag with a
    # '--gtest_' prefix as a request for help.
    if HAS_ABSL_FLAGS:
      self.TestUnknownFlagWithAbseil(UNKNOWN_GTEST_PREFIXED_FLAG)
    else:
      self.TestHelpFlag(UNKNOWN_GTEST_PREFIXED_FLAG)

  def testRunsTestsWithoutHelpFlag(self):
    """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.
    """

    self.TestNonHelpFlag(None)

  def testRunsTestsWithGtestInternalFlag(self):
    """Verifies correct behavior when internal testing flag is specified.

    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__':
  if '--has_absl_flags' in sys.argv:
    sys.argv.remove('--has_absl_flags')
  gtest_test_utils.Main()
