Python3.10: TestConvert::test_no_file - AssertionError: 'optional arguments:' not found in 'usage: m2r.py

[jsmolic]

When runing tests with Python 3.10.0b1 I get the following test failure:

=========================================================== FAILURES ===========================================================
___________________________________________________ TestConvert.test_no_file ___________________________________________________

self = <tests.test_cli.TestConvert testMethod=test_no_file>

    def test_no_file(self):
        p = subprocess.Popen(
            [sys.executable, '-m', 'm2r'],
            stdout=subprocess.PIPE,
        )
        p.wait()
        self.assertEqual(p.returncode, 0)
        with p.stdout as buffer:
            message = buffer.read().decode()
        self.assertIn('usage', message)
        self.assertIn('underscore-emphasis', message)
        self.assertIn('anonymous-references', message)
        self.assertIn('inline-math', message)
>       self.assertIn('optional arguments:', message)
E       AssertionError: 'optional arguments:' not found in 'usage: m2r.py [-h] [--overwrite] [--dry-run] [--no-underscore-emphasis] [--parse-relative-links] [--anonymous-references]\n              [--disable-inline-math]\n              [input_file ...]\n\npositional arguments:\n  input_file            files to convert to reST format\n\noptions:\n  -h, --help            show this help message and exit\n  --overwrite           overwrite output file without confirmaion\n  --dry-run             print conversion result and not save output file\n  --no-underscore-emphasis\n                        do not use underscore (_) for emphasis\n  --parse-relative-links\n                        parse relative links into ref or doc directives\n  --anonymous-references\n                        use anonymous references in generated rst\n  --disable-inline-math\n                        disable parsing inline math\n'

buffer     = <_io.BufferedReader name=11>
message    = ('usage: m2r.py [-h] [--overwrite] [--dry-run] [--no-underscore-emphasis] '
 '[--parse-relative-links] [--anonymous-references]\n'
 '              [--disable-inline-math]\n'
 '              [input_file ...]\n'
 '\n'
 'positional arguments:\n'
 '  input_file            files to convert to reST format\n'
 '\n'
 'options:\n'
 '  -h, --help            show this help message and exit\n'
 '  --overwrite           overwrite output file without confirmaion\n'
 '  --dry-run             print conversion result and not save output file\n'
 '  --no-underscore-emphasis\n'
 '                        do not use underscore (_) for emphasis\n'
 '  --parse-relative-links\n'
 '                        parse relative links into ref or doc directives\n'
 '  --anonymous-references\n'
 '                        use anonymous references in generated rst\n'
 '  --disable-inline-math\n'
 '                        disable parsing inline math\n')
p          = <Popen: returncode: 0 args: ['/usr/bin/python3.10', '-m', 'm2r']>
self       = <tests.test_cli.TestConvert testMethod=test_no_file>

tests/test_cli.py:62: AssertionError

[heirecka]

The possible fix in #62 works for me.