[3.8] bpo-29553: Fix ArgumentParser.format_usage() for mutually exclusive groups (GH-14976) (GH-15494) (GH-15624)
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index d6d1609..86ec6cc 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -2813,6 +2813,46 @@
-c c help
'''
+class TestMutuallyExclusiveNested(MEMixin, TestCase):
+
+ def get_parser(self, required):
+ parser = ErrorRaisingArgumentParser(prog='PROG')
+ group = parser.add_mutually_exclusive_group(required=required)
+ group.add_argument('-a')
+ group.add_argument('-b')
+ group2 = group.add_mutually_exclusive_group(required=required)
+ group2.add_argument('-c')
+ group2.add_argument('-d')
+ group3 = group2.add_mutually_exclusive_group(required=required)
+ group3.add_argument('-e')
+ group3.add_argument('-f')
+ return parser
+
+ usage_when_not_required = '''\
+ usage: PROG [-h] [-a A | -b B | [-c C | -d D | [-e E | -f F]]]
+ '''
+ usage_when_required = '''\
+ usage: PROG [-h] (-a A | -b B | (-c C | -d D | (-e E | -f F)))
+ '''
+
+ help = '''\
+
+ optional arguments:
+ -h, --help show this help message and exit
+ -a A
+ -b B
+ -c C
+ -d D
+ -e E
+ -f F
+ '''
+
+ # We are only interested in testing the behavior of format_usage().
+ test_failures_when_not_required = None
+ test_failures_when_required = None
+ test_successes_when_not_required = None
+ test_successes_when_required = None
+
# =================================================
# Mutually exclusive group in parent parser tests
# =================================================