Create argparse type "existing_dir[_empty]"

[pyi2ncommon] / test / test_argparse_helpers.py

# The software in this package is distributed under the GNU General
# Public License version 2 (with a special exception described below).
#
# A copy of GNU General Public License (GPL) is included in this distribution,
# in the file COPYING.GPL.
#
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# or inline functions from this file, or you compile this file and link it
# with other works to produce a work based on this file, this file
# does not by itself cause the resulting work to be covered
# by the GNU General Public License.
#
# However the source code for this file must still be made available
# in accordance with section (3) of the GNU General Public License.
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# This exception does not invalidate any other reasons why a work based
# on this file might be covered by the GNU General Public License.

""" test_argparse_helpers.py: unit tests for argparse_helpers

Test classes and functions in argparse_helpers

For help see :py:mod:`unittest`

.. codeauthor:: Intra2net
"""

import unittest
import os
from os.path import isfile, isdir
from shutil import rmtree
from tempfile import mkstemp, mkdtemp

# relative import of tested module ensures we do not test installed version
try:
    from src import argparse_helpers
except ImportError as ie:
    raise RuntimeError('Failed to import tested module argparse_helpers: {}'
                       .format(ie))


class ArgparseTester(unittest.TestCase):
    """ only test case in this module, see module doc for more help """

    def test_non_exit(self):
        """Check that NonExitingParser raises the right exception."""
        parser = argparse_helpers.NonExitingParser()
        parser.add_argument('-a', type=int)
        self.assertRaises(argparse_helpers.ArgParserWantsExit,
                          parser.parse_args, ['-a', 'blubb'])

    def test_existing_file(self):
        temp_file = None
        temp_handle = None
        try:
            # create a file
            temp_handle, temp_file = mkstemp()
            os.write(temp_handle, b'bla')
            os.close(temp_handle)
            temp_handle = None

            # test with existing file
            parser = argparse_helpers.NonExitingParser()
            parser.add_argument('--input', type=argparse_helpers.existing_file)
            parser.add_argument('--input2', type=argparse_helpers.existing_file_or_empty)
            parser.parse_args(['--input', temp_file, '--input2', temp_file])
        finally:
            if temp_handle:
                os.close(temp_handle)
            if temp_file and isfile(temp_file):
                os.remove(temp_file)

        # test with non-existing file
        self.assertRaisesRegex(argparse_helpers.ArgParserWantsExit,
                               'is not an existing file',
                               parser.parse_args,
                               ['--input', temp_file, ])

    def test_existing_dir(self):
        temp_dir = None
        try:
            # create a dir
            temp_dir = mkdtemp()

            # test with existing dir
            parser = argparse_helpers.NonExitingParser()
            parser.add_argument('--input', type=argparse_helpers.existing_dir)
            parser.add_argument('--input2', type=argparse_helpers.existing_dir_or_empty)
            parser.parse_args(['--input', temp_dir, '--input2', temp_dir])
        finally:
            if temp_dir and isdir(temp_dir):
                rmtree(temp_dir)

        # test with non-existing dir
        self.assertRaisesRegex(argparse_helpers.ArgParserWantsExit,
                               'is not an existing directory',
                               parser.parse_args,
                               ['--input', temp_dir, ])

    def test_allow_empty(self):
        parser = argparse_helpers.NonExitingParser()
        parser.add_argument('--file', type=argparse_helpers.existing_file_or_empty)
        parser.add_argument('--dir', type=argparse_helpers.existing_dir_or_empty)

        # both emtpy: no problem
        parser.parse_args(['--file', '', '--dir', ''])

        # test with non-existing file/dir
        self.assertRaisesRegex(argparse_helpers.ArgParserWantsExit,
                               'is not an existing file',
                               parser.parse_args,
                               ['--dir', '', '--file', 'not-an-existing-file'])
        self.assertRaisesRegex(argparse_helpers.ArgParserWantsExit,
                               'is not an existing directory',
                               parser.parse_args,
                               ['--file', '', '--dir', 'not-an-existing-dir'])


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