import argparse
import unittest


MUTEX_HELP_HAS_NO_TITLE = """usage: PROG_CMD [-h] [--arg1 ARG1] [--arg2 ARG2]

Program description

optional arguments:
  -h, --help   show this help message and exit

  --arg1 ARG1  arg1 help
  --arg2 ARG2  arg2 help

Epilog
"""


MUTEX_HELP_INCLUDES_TITLE = """usage: PROG_CMD [-h] [--arg1 ARG1] [--arg2 ARG2]

Program description

optional arguments:
  -h, --help   show this help message and exit

Group title:
  Group description

  --arg1 ARG1  arg1 help
  --arg2 ARG2  arg2 help

Epilog
"""


class EntitledMutexTestCase(unittest.TestCase):

    def test_mutex_without_title_or_description(self):

        parser = argparse.ArgumentParser(
            prog='PROG_CMD',
            description='Program description',
            epilog='Epilog')

        mutex_group = parser.add_mutually_exclusive_group()
        mutex_group.add_argument('--arg1', help='arg1 help')
        mutex_group.add_argument('--arg2', help='arg2 help')

        help_string = parser.format_help()
        self.assertEqual(help_string, MUTEX_HELP_HAS_NO_TITLE)

    def test_mutex_with_title_and_description(self):

        parser = argparse.ArgumentParser(
            prog='PROG_CMD',
            description='Program description',
            epilog='Epilog')

        mutex_group = parser.add_mutually_exclusive_group(
            title='Group title',
            description='Group description')
        mutex_group.add_argument('--arg1', help='arg1 help')
        mutex_group.add_argument('--arg2', help='arg2 help')

        help_string = parser.format_help()
        self.assertEqual(help_string, MUTEX_HELP_INCLUDES_TITLE)


if __name__ == "__main__":
    unittest.main()