Added tests for token_resembles_flag

Author: kmvanbrunt

cmd2/argparse_completer.py

@@ -209,7 +209,7 @@ def register_custom_actions(parser: argparse.ArgumentParser) -> None:
     parser.register('action', 'append', _AppendRangeAction)
 
 
-def token_resembles_flag(token: str, parser: argparse.ArgumentParser):
+def token_resembles_flag(token: str, parser: argparse.ArgumentParser) -> bool:
     """Determine if a token looks like a flag. Based on argparse._parse_optional()."""
     # if it's an empty string, it was meant to be a positional
     if not token:
@@ -236,6 +236,7 @@ def token_resembles_flag(token: str, parser: argparse.ArgumentParser):
     # Looks like a flag
     return True
 
+
 class AutoCompleter(object):
     """Automatically command line tab completion based on argparse parameters"""
 

tests/test_acargparse.py

@@ -5,7 +5,7 @@
 Released under MIT license, see LICENSE file
 """
 import pytest
-from cmd2.argparse_completer import ACArgumentParser
+from cmd2.argparse_completer import ACArgumentParser, token_resembles_flag
 
 
 def test_acarg_narg_empty_tuple():
@@ -51,3 +51,18 @@ def test_acarg_narg_tuple_zero_base():
 def test_acarg_narg_tuple_zero_to_one():
     parser = ACArgumentParser(prog='test')
     parser.add_argument('tuple', nargs=(0, 1))
+
+
+def test_token_resembles_flag():
+    parser = ACArgumentParser()
+
+    # Not valid flags
+    assert not token_resembles_flag('', parser)
+    assert not token_resembles_flag('non-flag', parser)
+    assert not token_resembles_flag('-', parser)
+    assert not token_resembles_flag('--has space', parser)
+    assert not token_resembles_flag('-2', parser)
+
+    # Valid flags
+    assert token_resembles_flag('-flag', parser)
+    assert token_resembles_flag('--flag', parser)