From f27c1a1eaa5b512be21af062280c5b765e6955b0 Mon Sep 17 00:00:00 2001
From: hanjinpeng <hanjinpeng@kylinos.cn>
Date: Sun, 13 Sep 2026 21:48:47 -0400
Subject: [PATCH] config: raise NotImplementedError from abstract
 ConfigNamespace methods

ConfigNamespace._getitem() and __iter__() returned a NotImplementedError
instance instead of raising it (see the FIXME).  As a result
'key in ConfigNamespace()' was always True and iter() failed with a
confusing TypeError.  Raise the exception as intended.
---
 iniparse/config.py |  5 ++---
 tests/test_ini.py  | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/iniparse/config.py b/iniparse/config.py
index 00800c3..5c408dd 100644
--- a/iniparse/config.py
+++ b/iniparse/config.py
@@ -23,7 +23,7 @@ class ConfigNamespace:
     # Methods that must be implemented by subclasses
 
     def _getitem(self, key: str) -> object:
-        return NotImplementedError(key)
+        raise NotImplementedError(key)
 
     def __setitem__(self, key: str, value: object):
         raise NotImplementedError(key, value)
@@ -32,8 +32,7 @@ def __delitem__(self, key: str) -> None:
         raise NotImplementedError(key)
 
     def __iter__(self) -> Iterable[str]:
-        # FIXME Raise instead return
-        return NotImplementedError()
+        raise NotImplementedError()
 
     def _new_namespace(self, name: str) -> "ConfigNamespace":
         raise NotImplementedError(name)
diff --git a/tests/test_ini.py b/tests/test_ini.py
index 359a2b9..5b23b41 100644
--- a/tests/test_ini.py
+++ b/tests/test_ini.py
@@ -833,3 +833,25 @@ def test_option_continuation_single(self):
         ip.section.option = '\n'.join(['', '', '', 'foo', '', '', ''])
         ip.section.another = 'baz'
         self.assertEqual(str(ip), self.s6)
+
+
+class TestConfigNamespaceAbstract(unittest.TestCase):
+    def test_abstract_methods_raise(self):
+        """
+        :id: 855cbd60-05d1-449f-91c0-d77a8dfa2e59
+        :title: Abstract ConfigNamespace methods raise NotImplementedError
+        :description:
+            Verifies that the abstract _getitem() and __iter__() methods of
+            ConfigNamespace raise NotImplementedError instead of returning
+            the exception object (which made `key in ns` always True).
+        :tags: Tier 3
+        :steps:
+            1. Create a bare ConfigNamespace.
+            2. Check membership and iterate over it.
+        :expectedresults:
+            1. Object is created.
+            2. NotImplementedError is raised in both cases.
+        """
+        ns = config.ConfigNamespace()
+        self.assertRaises(NotImplementedError, lambda: 'key' in ns)
+        self.assertRaises(NotImplementedError, iter, ns)