gh-92886: [clinic.py] raise exception on invalid input instead of assertion (GH-98051)

Tests should pass with -O (assertions off).

Automerge-Triggered-By: GH:iritkatriel

Author: iritkatriel

Lib/test/test_clinic.py

@@ -153,7 +153,7 @@ def test_right_only(self):
     def test_have_left_options_but_required_is_empty(self):
         def fn():
             clinic.permute_optional_groups(['a'], [], [])
-        self.assertRaises(AssertionError, fn)
+        self.assertRaises(ValueError, fn)
 
 
 class ClinicLinearFormatTest(TestCase):

Tools/clinic/clinic.py

@@ -495,7 +495,8 @@ def permute_optional_groups(left, required, right):
     result = []
 
     if not required:
-        assert not left
+        if left:
+            raise ValueError("required is empty but left is not")
 
     accumulator = []
     counts = set()