1 files changed, 33 insertions, 0 deletions
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index a0b9162..d7f90cd 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -753,6 +753,39 @@ class TestOptionalsActionCount(ParserTestCase):
     ]
 
 
+class TestOptionalsAllowLongAbbreviation(ParserTestCase):
+    """Allow long options to be abbreviated unambiguously"""
+
+    argument_signatures = [
+        Sig('--foo'),
+        Sig('--foobaz'),
+        Sig('--fooble', action='store_true'),
+    ]
+    failures = ['--foob 5', '--foob']
+    successes = [
+        ('', NS(foo=None, foobaz=None, fooble=False)),
+        ('--foo 7', NS(foo='7', foobaz=None, fooble=False)),
+        ('--fooba a', NS(foo=None, foobaz='a', fooble=False)),
+        ('--foobl --foo g', NS(foo='g', foobaz=None, fooble=True)),
+    ]
+
+
+class TestOptionalsDisallowLongAbbreviation(ParserTestCase):
+    """Do not allow abbreviations of long options at all"""
+
+    parser_signature = Sig(allow_abbrev=False)
+    argument_signatures = [
+        Sig('--foo'),
+        Sig('--foodle', action='store_true'),
+        Sig('--foonly'),
+    ]
+    failures = ['-foon 3', '--foon 3', '--food', '--food --foo 2']
+    successes = [
+        ('', NS(foo=None, foodle=False, foonly=None)),
+        ('--foo 3', NS(foo='3', foodle=False, foonly=None)),
+        ('--foonly 7 --foodle --foo 2', NS(foo='2', foodle=True, foonly='7')),
+    ]
+
 # ================
 # Positional tests
 # ================