Support positional args with dashes

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 
 ## [Unreleased] - unreleased
+### Fixed
+- Fix for support of positionals with dashes in them.  They are converted
+  to underscores just like they are for optionals.
 
 
 ## [5] - 2017-04-10

shellish/command/supplement.py

@@ -362,6 +362,10 @@ def add_subparsers(self, prog=None, **kwargs):
             prog = f.format_help().strip()
         return super().add_subparsers(prog=prog, **kwargs)
 
+    def _get_positional_kwargs(self, dest, **kwargs):
+        dest = dest.replace('-', '_')
+        return super()._get_positional_kwargs(dest, **kwargs)
+
 
 class SafeFileContext(object):
     """ Used by SafeFileType to provide a file-like context manager. """

test/command.py

@@ -153,3 +153,20 @@ def run(args):
         cmd = shellish.Command(name='test', run=run)
         cmd.add_file_argument('--foo', mode='w')
         cmd(argv='--foo makethis')
+
+
+class ArgumentDestSafety(unittest.TestCase):
+
+    def test_dash_positional(self):
+        c = shellish.Command(name='test_dash')
+        c.add_argument('foo-bar')
+        args = c.argparser.parse_known_args(['value'])[0]
+        self.assertIn('foo_bar', args)
+        self.assertEqual(args.foo_bar, 'value')
+
+    def test_dash_opt(self):
+        c = shellish.Command(name='test_dash')
+        c.add_argument('--foo-bar')
+        args = c.argparser.parse_known_args(['--foo-bar', 'value'])[0]
+        self.assertIn('foo_bar', args)
+        self.assertEqual(args.foo_bar, 'value')